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Non-invasive automated sphygmomanometers

Sphygmomanomètres non invasifs automatiques

OIM

L R

16-

2 Ed

ition

2002

(E)

OIML R 16-2Edition 2002 (E)

ORGANISATION INTERNATIONALE

DE MÉTROLOGIE LÉGALE

INTERNATIONAL ORGANIZATION

OF LEGAL METROLOGY

INTERNATIONAL

RECOMMENDATION

OIML R 16-2: 2002 (E)

2

Contents

Foreword ........................................................................................................................................................................... 3

1 Scope ........................................................................................................................................................................... 4

2 Terminology ................................................................................................................................................................ 4

3 Description of the category of instrument ................................................................................................................ 5

4 Units of measurement ................................................................................................................................................ 5

5 Metrological requirements ......................................................................................................................................... 5

6 Technical requirements .............................................................................................................................................. 6

7 Metrological controls ................................................................................................................................................. 8

Annex A: Test procedures (Mandatory) ....................................................................................................................... 10

Annex B: Test report format (Mandatory for application within the OIML Certificate System for Measuring Instruments) ................................................................................. 19

Annex C: Rationale for the maximum permissible errors of the overall system (Informative) .............................. 36

OIML R 16-2: 2002 (E)

3

The International Organization of Legal Metrology(OIML) is a worldwide, intergovernmental organizationwhose primary aim is to harmonize the regulations and

metrological controls applied by the national metrologicalservices, or related organizations, of its Member States.

The two main categories of OIML publications are:

• International Recommendations (OIML R), which aremodel regulations that establish the metrological charac-teristics required of certain measuring instruments andwhich specify methods and equipment for checking theirconformity; the OIML Member States shall implementthese Recommendations to the greatest possible extent;

• International Documents (OIML D), which are inform-ative in nature and intended to improve the work of themetrological services.

OIML Draft Recommendations and Documents are devel-oped by technical committees or subcommittees which areformed by the Member States. Certain international andregional institutions also participate on a consultation basis.

Cooperative agreements are established between OIML andcertain institutions, such as ISO and IEC, with the objectiveof avoiding contradictory requirements; consequently, manu-facturers and users of measuring instruments, test labor-

atories, etc. may apply simultaneously OIML publicationsand those of other institutions.

International Recommendations and International Docu-ments are published in French (F) and English (E) and aresubject to periodic revision.

This publication - reference OIML R 16-2 Edition 2002 (E) -was developed by the OIML Technical SubcommitteeTC 18/SC 1 Blood pressure instruments. This publication wasapproved for final publication by the InternationalCommittee of Legal Metrology in 2001 and will be submittedto the International Conference of Legal Metrology in 2004for formal sanction.

OIML Recommendation R 16 includes two parts: Part 1(Non-invasive mechanical sphygmomanometers) and Part 2(Non-invasive automated sphygmomanometers) which havebeen issued in 2002 as separate publications. It supersedesthe former editions dated 1973 (English version) and 1970(French version).

OIML publications may be obtained from the Organization’sheadquarters:

Bureau International de Métrologie Légale11, rue Turgot - 75009 Paris - FranceTelephone: 33 (0)1 48 78 12 82 and 42 85 27 11Fax: 33 (0)1 42 82 17 27E-mail: [email protected]: www.oiml.org

Foreword

OIML R 16-2: 2002 (E)

4

1 Scope

This Recommendation specifies general, performance,efficiency and mechanical and electrical safety require-ments, including test methods for type approval, fornon-invasive electronic or automated sphygmomano-meters and their accessories which, by means of aninflatable cuff, are used for the non-invasivemeasurement of arterial blood pressure.

This Recommendation only applies to devicesmeasuring at the upper arm, the wrist or the thigh.

Note: Luer locks shall not be used with these devices(see 6.11.3 and 7.5).

2 Terminology

2.1 Bladder

Inflatable component of the cuff.

2.2 Pressure in a blood vessel

Pressure in the arterial system of the body.

2.3 Cuff

Component of the sphygmomanometer, comprising abladder and a sleeve, which is wrapped around thelimb of the patient.

2.4 Diastolic blood pressure (value)

Minimum value of the arterial blood pressure as aresult of relaxation of the systemic ventricle.

Note: Because of hydrostatic effects, this value shouldbe measured with the cuff at the heart level.

2.5 Mean arterial blood pressure (value)

Value of the integral of one cycle of the blood pressurecurve divided by the time of one heart beat period.


2.6 Non-invasive blood pressure measurement

Indirect measurement of the arterial blood pressurewithout arterial puncture.

2.7 Pneumatic system

System that includes all pressurized and pressure-controlling parts such as cuff, tubing, connectors,valves, transducer and pump.

2.8 Sleeve

Essentially inelastic part of the cuff that encloses thebladder.

2.9 Sphygmomanometer

Instrument used for the non-invasive measurement ofthe arterial blood pressure.

2.10 Systolic blood pressure (value)

Maximum value of the arterial blood pressure as aresult of the contraction of the systemic ventricle.


Non-invasive automated sphygmomanometers

OIML R 16-2: 2002 (E)

5

2.11 Electro-mechanical blood pressuremeasuring system

System that consists of:

• at least one cuff, which is connected to thepneumatic system;

• at least one electro-mechanical transducer tomeasure cuff pressure;

• at least one measured value display; and• if needed, signal inputs and outputs.

2.12 Electro-mechanical pressure transducer

Component that transforms pressure signals intoelectrical signals.

2.13 Oscillometric method

Method, wherein a cuff is placed on the limb and thepressure in the cuff is increased until the blood flow inthe artery is interrupted and then the pressure in thecuff is slowly reduced.

Note: During the inflation and deflation of the cuffsmall pressure changes (oscillations) occur inthe cuff as a result of the arterial blood pressurepulses. These oscillations, which first increaseand then decrease, are detected and storedtogether with the corresponding cuff pressurevalues in the measurement system. With thesestored values the systolic, diastolic and meanarterial blood pressure values can bemathematically derived using an appropriatealgorithm. It is possible to carry out themeasurement during the inflation phase.

2.14 Zero setting

Procedure that corrects a deviation of the pressurereading to 0 kPa (0 mmHg) at atmospheric pressure(gauge pressure: 0 kPa (0 mmHg)).

2.15 Patient simulator

Device for simulating the oscillometric cuff pulsesand/or auscultatory sounds during inflation anddeflation.

Note: This device is not used for testing accuracy but isrequired in assessing stability of performance.

2.16 Auscultatory method

Technique whereby sounds (known as Korotkoffsounds) are heard over an occluded artery as theoccluding pressure is slowly released, the appearanceof sounds coinciding with the systolic blood pressureand the disappearance of sounds with the diastolicblood pressure. In children under the age of 13, “k4”(i.e. 4th phase Korotkoff sound) may be appropriate.

2.17 Self-linearizing deflation valve

Valve for controlled linearizing exhaust of thepneumatic system during measurement.

3 Description of the category of instrument

The basic components of a sphygmomanometer are acuff and bladder that can be wrapped around apatient’s limb, a system for applying and releasingpressure to the bladder, and a means of measuring anddisplaying the instantaneous pressure in the bladder.

4 Units of measurement

The blood pressure shall be indicated either in kilo-pascals (kPa) or in millimeters of mercury (mmHg).

5 Metrological requirements

5.1 Maximum permissible errors of the cuffpressure indication

For any set of conditions within the ambienttemperature range of 15 °C to 25 °C and the relativehumidity range of 20 % to 85 %, both for increasingand for decreasing pressure, the maximum permissibleerror for the measurement of the cuff pressure at anypoint of the scale range shall be ± 0.4 kPa (± 3 mmHg)in case of verifying the first time and ± 0.5 kPa(± 4 mmHg) for sphygmomanometers in use.

Testing shall be carried out in accordance with A.2.

OIML R 16-2: 2002 (E)

6

5.2 Maximum permissible errors of the overallsystem as measured by clinical tests*

The following maximum permissible errors shall applyfor the overall system:• maximum mean error of measurement: ± 0.7 kPa

(± 5 mmHg);• maximum experimental standard deviation: 1.1 kPa

(8 mmHg).

For further recommended test methods see Annex C.

5.3 Environmental performance

5.3.1 Storage

Blood pressure measuring systems shall maintain therequirements specified in this Recommendation afterstorage for 24 h at a temperature of – 5 °C and for 24 hat a temperature of 50 °C and a relative humidity of85 % (non-condensing).

Testing shall be carried out at environmentalconditions (see 5.1) in accordance with A.2 after thetest sample has been placed for 24 h at a temperatureof – 5 °C and immediately afterwards for 24 h at atemperature of 50 °C in a climatic chamber.

Note: Integrated multiparameter monitors maycontain components which may be damagedduring storage. The general temperature rangeas stated in A.3 has therefore been reducedcompared to the requirements in R 16-1.

5.3.2 Temperature, relative humidity

For the ambient temperature range of 10 °C to 40 °Cand a relative humidity of 85 % (non-condensing), thedifference of the cuff pressure indication of thesphygmomanometer shall not exceed ± 0.4 kPa(± 3 mmHg).

Testing shall be carried out in accordance with A.2 andA.11.

The signal processing for the determination of theblood pressure values shall not be influenced withinthe range of temperature and relative humidity. For anyset of conditions all the deviations between thereference pressure and the indicating cuff pressure ofthe instrument must be less than or equal to themaximum permissible error.

6 Technical requirements

6.1 General

Equipment, or parts thereof, using materials or havingforms of construction different from those detailed inthis Recommendation shall be accepted if it can bedemonstrated that an equivalent degree of safety andperformance is obtained.

6.2 Technical requirements for the cuff andbladder

The cuff shall contain a bladder. For reusable cuffs themanufacturer shall indicate the method for cleaning inthe accompanying documents (see 7.5).

Note: The optimum bladder size is one withdimensions such that its width is 40 % of thelimb circumference at the midpoint of the cuffapplication and its length is at least 80 %,preferably 100 % of the limb circumference atthe midpoint of cuff application. Use of thewrong size can affect the accuracy of themeasurement.

6.3 Technical requirements for the display

The display shall be designed and arranged so that theinformation including measuring values can be readand easily recognized.

Testing shall be carried out by visual inspection.

If abbreviations are used on the display they shall be asfollows:• “S” or “SYS”: systolic blood pressure (value);• “D” or “DIA”: diastolic blood pressure (value);• “M” or “MAP”: mean arterial blood pressure (value).

Single letter abbreviations shall be positioned in such away to avoid confusion with SI units.

6.4 Effect of voltage variations of the powersource

6.4.1 Internal electrical power source

6.4.1.1 Changes of the voltage within the workingrange determined according to A.4.1 shall not influencethe cuff pressure reading and the result of the bloodpressure measurement.* carried out by the manufacturer

OIML R 16-2: 2002 (E)

7

6.4.1.2 Outside this working range no cuff pressurereading and no result of the blood pressuremeasurement shall be displayed.

Testing shall be carried out in accordance with A.4.1and A.5.1.

6.4.2 External electrical power source

6.4.2.1 Changes of the voltage within the workingrange specified by the manufacturer (see 7.5) shall notinfluence the cuff pressure reading and the result of theblood pressure measurement.

Testing shall be carried out according to A.4.2 and A.5.2(alternating current) or A.4.3 and A.5.3 (direct current).

6.4.2.2 Incorrect values resulting from voltagevariations outside the limits given in 6.4.2.1 shall not bedisplayed.

Testing shall be carried out according to A.4.4(alternating current) and A.4.5 (direct current).

Note: In the case of any malfunction of the equipment,deflation to below 2 kPa (15 mmHg) must beguaranteed within 180 s in the case of adultpatients and to below 0.7 kPa (5 mmHg) within90 s in the case of neonatal/infant patients.


6.5.1 Air leakage

Air leakage shall not exceed a pressure drop of0.8 kPa/min (6 mmHg/min).


6.5.2 Pressure reducing system for devices using the auscultatory method

The pressure reducing system for manually operatedand automated deflation valves shall be capable ofmaintaining a deflation rate of 0.3 kPa/s to 0.4 kPa/s(2 mmHg/s to 3 mmHg/s) within the target range ofsystolic and diastolic blood pressure. For devices whichcontrol the pressure reduction as a function of thepulse rate, a deflation rate of 0.3 kPa/pulse to0.4 kPa/pulse (2 mmHg/pulse to 3 mmHg/pulse) shallbe maintained.

Note: Manually operated deflation valves should beeasily adjustable to these values.


6.5.3 Rapid exhaust

During the rapid exhaust of the pneumatic system,with the valve fully opened, the time for the pressurereduction from 35 kPa to 2 kPa (260 mmHg to15 mmHg) shall not exceed 10 s.

For blood pressure measuring systems having thecapability to measure in a neonatal/infant mode, thetime for the pressure reduction from 20 kPa to 0.7 kPa(150 mmHg to 5 mmHg) during the rapid exhaust ofthe pneumatic system with the valve fully opened shallnot exceed 5 s.


6.5.4 Zero setting

Blood pressure measuring systems shall be capable ofautomatic zero setting. The zero setting shall be carriedout at appropriate intervals, at least starting afterswitching on the device. At the moment of the zerosetting a gauge pressure of 0 kPa (0 mmHg) shall existand be displayed thereafter.

Devices performing zero setting only immediately afterswitching on, shall switch off automatically when thedrift of the pressure transducer and the analog signalprocessing exceeds 0.1 kPa (1 mmHg).


6.6 Electromagnetic compatibility

Either:• electrical and/or electromagnetic interferences shall

not lead to degradations in the cuff pressureindication or in the result of the blood pressuremeasurement; or

• if electrical and/or electromagnetic interferenceslead to an abnormality, the abnormality shall beclearly indicated and it shall be possible to restorenormal operation within 30 s after cessation of theelectromagnetic disturbance.

Testing should be carried out in accordance with therelevant OIML provisions (notably those of OIML D 11).

6.7 Stability of the cuff pressure indication

The change in the cuff pressure indication shall not bemore than 0.4 kPa (3 mmHg) throughout the pressurerange after 10 000 simulated measurement cycles.


OIML R 16-2: 2002 (E)

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6.8 Pressure indicating device

6.8.1 Nominal range and measuring range

The nominal range for the cuff pressure measurementshall be specified by the manufacturer. The measuringand indication ranges of the cuff pressure shall beequal to the nominal range. Values of blood pressuremeasurement results outside the nominal range of cuffpressure shall be clearly indicated as out of range.


6.8.2 Digital indication

The digital scale interval shall be 0.1 kPa (1 mmHg).

If the measured value of a parameter is to be indicatedon more than one display, all the displays shall indicatethe same numerical value.

Measured numerical values on the display(s), and thesymbols defining the units of measurement shall bearranged in such a way so as to avoid misinterpreta-tion.

Numbers and characters should be clearly legible.


6.9 Signal input and output ports

The construction of the signal input and output ports(excluding internal interfaces, e.g. microphone signalinput) relevant to the non-invasive blood pressuremeasurement shall ensure that incorrectly fitted ordefective accessories shall not result in erroneousindication of cuff pressure or erroneous indication ofblood pressure.


6.10 Alarms

If alarms are used they shall be of at least mediumpriority.

6.11 Safety

6.11.1 Cuff pressure

It shall be possible to abort any blood pressuremeasurement at any time by single key operation andthis shall lead to a rapid exhaust (see 6.5.3).


6.11.2 Unauthorized access

All controls which affect accuracy shall be sealedagainst unauthorized access.


6.11.3 Tubing connectors

Users of equipment intended for use in environmentsemploying intervascular fluid systems shall take allnecessary precautions to avoid connecting the outputof the blood pressure measuring device to such systemsas air might inadvertently be pumped into a bloodvessel if, for example, Luer locks were used.

6.11.4 Electrical safety

Electronic or automated sphygmomanometers shallcomply with the relevant national safety regulations.

6.11.5 Resistance to vibration and shock

The sphygmomanometer shall comply with therelevant provisions of OIML D 11 (e.g. subclause A.2.2of the 1994 edition, Mechanical conditions).

After testing, the device shall comply with the require-ments of 5.1 (of this Recommendation).

7 Metrological controls

Regional or national regulations may prescribe typeapproval, initial and/or periodic verification for non-invasive sphygmomanometers. These controls shallmeet the following conditions.

7.1 Type approval

At least three samples of a new type of sphygmomano-meter shall be tested.

The tests to verify conformity to metrological andtechnical requirements shall be carried out accordingto Annex A. A test report shall be prepared according toAnnex B.

OIML R 16-2: 2002 (E)

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7.2 Verification

7.2.1 Initial verification

At initial verification the requirements of 5.1 and 6.5.1shall be fulfilled.

Testing shall be carried out according to A.2 and A.6.

7.2.2 Subsequent verification

Each instrument of an approved type of sphygmo-manometer shall be verified every 2 years or afterrepair. At least 5.1 and 6.5.1 shall be fulfilled and testsmust be carried out according to A.2 and A.6.

7.3 Sealing

7.3.1 Control marks will be put on lead seals for whichcorresponding punched screws shall be attachedwhenever necessary. These seals shall prevent, withoutdestruction of the control marks:

• in the case of patient-monitors in which thesphygmomanometer is one part of a system: themanipulation of the metrologically relevant parts formeasuring blood pressure;

• in the case of all other manometers: the opening ofthe casing.

7.3.2 If the construction of the instrument guaranteessecurity against any interference, the metrologicalcontrol marks or the security marks may be attached inthe form of labels.

7.3.3 All seals shall be accessible without using a tool.

7.4 Marking of the device

The device shall be marked with the followinginformation:

• name and/or trademark of manufacturer;• serial number and year of fabrication;• measuring range and measuring unit;• type approval number (if applicable);• center of the bladder, indicating the correct position

for the cuff over the artery; and

• marking on the cuff indicating the limb circumfer-ence for which it is appropriate (see 6.2).

7.5 Manufacturer’s information

Information supplied by the manufacturer shallcomply with the specifications and requirements givenin this Recommendation.

The manufacturer’s instruction manual shall containthe following information:• reference to OIML R 16-2 including the complete

title;• explanation of the operating procedures which are

important for correct application (such as theselection of the appropriate cuff size, positioning ofthe cuff and adjustment of the pressure reductionrate);

• a warning to users of equipment intended for use inenvironments employing intervascular fluid systemsnot to connect the output of the blood pressuremeasuring device to such systems as air mightinadvertently be pumped into a blood vessel if, forexample, Luer locks were used;

• methods for cleaning reusable cuffs;• nature and frequency of the maintenance to ensure

that the device operates properly and safely at alltimes; it is recommended that the performanceshould be checked at least every 2 years and aftermaintenance and repair, by re-verifying at least therequirements in 5.1 and 6.5.1 (testing at least at7 kPa (50 mmHg) and 27 kPa (200 mmHg));

• a reference method for clinical tests carried outaccording to Annex C or an equivalent method;

• a list of all components belonging to the pressuremeasuring system, including accessories;

• a description of the operating principles of the bloodpressure measuring device;

• remarks on the environmental or operational factorswhich may affect the performance (e.g. electro-magnetic fields, arrythmia);

• specification of the signal input/output port(s);• specification of the rated voltage, if applicable;• specification of the intended power source, if

applicable;• nominal range for the result of the blood pressure

measurement;• warm up time, if applicable;• description of the meaning of the “out of range

signal” (see 6.4.1.2 and 6.4.2.2, if applicable); and• description of the alarms, if applicable.

OIML R 16-2: 2002 (E)

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A.1 General

For digital indications an uncertainty of 0.1 kPa (1 mmHg) shall be allowed in any displayed value,because the display system cannot indicate a change ofless than one unit.

A.2 Method of test for the maximumpermissible errors of the cuff pressure indication

Requirements in 5.1 shall apply.

A.2.1 Apparatus

• rigid metal vessel with a capacity of 500 ml ± 5 %;

• calibrated reference manometer with an uncertaintyless than 0.1 kPa (0.8 mmHg);

• pressure generator, e.g. ball pump (hand pump) witha deflation valve;

• T-piece connectors and hoses.

A.2.2 Procedure

Replace the cuff with the vessel. Connect the calibratedreference manometer by means of a T-piece connectorand hoses to the pneumatic circuit (see Figure 1). Afterdisabling the electro-mechanical pump (if fitted),connect the additional pressure generator into thepressure system by means of another T-piececonnector. Carry out the test in pressure steps of notmore than 7 kPa (50 mmHg) between 0 kPa (0 mmHg)and the maximum pressure of the scale range.*

A.2.3 Expression of results

Express the results as the differences between theindicated pressure of the manometer of the device to betested and the corresponding readings of the referencemanometer (see B.2).

A.3 Method of test for the influence of temperature on cuff pressure indication

A.3.1 Apparatus

• apparatus as specified in A.2.1; plus• climatic chamber.

Annex A

Test procedures

(Mandatory)

* In case of doubt about the linearity, spot checks should becarried out or the width of the pressure steps should be reduced,i.e., from the normally recommended 7 kPa (50 mmHg) to 3 kPa(20 mmHg). This also applies to Table 1 in Annex B.

1 - Reference manometer 2 - Device to be tested 3 - Metal vessel 4 - Pressure generator

Figure 1 Measurement system for determining the limits of errorof the cuff pressure indication

1111 2222 3333 4444

500 ml

21

43

1111 2222 3333 4444

OIML R 16-2: 2002 (E)

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A.3.2 Procedure

Replace the cuff with the vessel. Connect the calibratedreference manometer by means of a T-piece connectorto the pneumatic system (see Figure 2). After disablingthe electro-mechanical pump (if fitted), connect theadditional pressure generator into the pneumaticsystem by means of another T-piece connector.

For each of the following combinations of temperatureand humidity, condition the device for at least 3 h in theclimatic chamber to allow the device to reach steadyconditions:• 10 °C ambient temperature, 85 % relative humidity

(non-condensing);• 20 °C ambient temperature, 85 % relative humidity


(non-condensing).

Carry out the test of the cuff pressure indication asdescribed in A.2.2 for each of the combinations oftemperature and humidity mentioned above.


Express the results as the differences between theindicated pressure of the manometer of the device to betested and the corresponding indications of thereference manometer (see B.3) at the relevanttemperature value.

A.4 Test methods for the effect of voltagevariations of the power source on thecuff pressure indication

A.4.1 Internal electrical power source

A.4.1.1 Apparatus

• adjustable direct current voltage supply;• voltmeter with an uncertainty of less than 0.5 % of

the measured value;• calibrated reference manometer with an uncertainty

of less than 0.1 kPa (0.8 mmHg).

1111 2222 3333 4444

500 ml

21

3

45

1111 2222 3333 4444

1 - Reference manometer 2 - Climatic chamber 3 - Device to be tested 4 - Metal vessel 5 - Pressure generator

Figure 2 Measurement system for determining the influence of temperature

OIML R 16-2: 2002 (E)

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A.4.1.2 Procedure

Replace the internal electrical power source of theblood pressure measuring system with a DC voltagesupply having an impedance which is equivalent to theimpedance of the internal electrical power sourcespecified by the manufacturer. Measure the variation inapplied DC voltage supply with a voltmeter. Test theblood pressure measuring system by altering the DCvoltage supply in steps of 0.1 V and determine thelowest voltage limit at which the cuff pressure readingis still displayed.

Carry out the test with the maximum permissibleimpedance of the internal electrical power source.

Carry out the test according to the procedure specifiedin A.2 at the lowest voltage limit increased by 0.1 V andalso at the nominal voltage.

A.4.1.3 Expression of results

Express the results as the difference between the cuffpressure indication of the blood pressure measuringsystem to be tested and that of the reference mano-meter at the lowest voltage limit increased by 0.1 V andat nominal voltage.

A.4.2 External electrical power source -alternating current

A.4.2.1 Apparatus

• adjustable alternating current voltage supply;• voltmeter with an uncertainty of less than 0.5 % of

the measured value;• calibrated reference manometer with an uncertainty

of less than 0.1 kPa (0.8 mmHg).

A.4.2.2 Procedure

Connect the blood pressure measuring system to theadjustable alternating current voltage supply. Measurethe variation in AC voltage supply with the voltmeter.

Carry out the test according to the procedure specifiedin A.2 at:• the maximum rated voltage, declared by the

manufacturer, increased by 10 %;• the mean value of the maximum and minimum rated

voltage, declared by the manufacturer;• the minimum rated voltage, declared by the

manufacturer, decreased by 10 %.


Express the results as the difference between the cuffpressure indication of the blood pressure measuringsystem to be tested and that of the reference mano-meter.

A.4.3 External electrical power source - direct current

A.4.3.1 Apparatus

Use the apparatus listed in A.4.1.1.

A.4.3.2 Procedure

Connect the blood pressure measuring system to theDC voltage supply. Control the DC voltage supply byreference to a voltmeter.

Carry out the test according to the procedure specifiedin A.2 at:• the maximum rated voltage, declared by the manu-

facturer, increased by 10 %;• the mean value of the maximum and minimum rated

voltage, declared by the manufacturer;• the minimum rated voltage, declared by the manu-

facturer, decreased by 10 %.


Express the results as the difference between the cuffpressure indication of the blood pressure measuringsystem to be tested and that of the reference mano-meter.

A.4.4 Voltage variations of the external electricalpower source - alternating current

A.4.4.1 Apparatus


A.4.4.2 Procedure

Connect the blood pressure measuring system to theAC voltage supply. Measure the variation in the ACvoltage supply with the voltmeter.

Test the blood pressure measuring system by alteringthe AC voltage supply in steps of 5 V and determine thelowest voltage limit at which the cuff pressure readingis displayed.

OIML R 16-2: 2002 (E)

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Carry out the test according to the procedure specifiedin A.2 at the lowest voltage limit increased by 5 V andalso at the rated voltage.


Express the results as the difference between the cuffpressure indication of the blood pressure measuringsystem to be tested and that of the reference mano-meter at rated voltage and the lowest voltage limitincreased by 5 V.

A.4.5 Voltage variations of the external electricalpower source - direct current

A.4.5.1 Apparatus


A.4.5.2 Procedure

Connect the blood pressure measuring system to theDC voltage supply. Measure the variation in the DCvoltage supply with the voltmeter.

Test the blood pressure measuring system by alteringthe DC voltage supply in steps of 0.1 V and determinethe lowest voltage limit at which the cuff pressurereading is displayed.

Carry out the test according to the procedure specifiedin A.2 at the lowest voltage limit increased by 0.1 V andalso at the rated voltage.


Express the results as the difference between the cuffpressure indication of the blood pressure measuringsystem to be tested and that of the reference mano-meter at rated voltage and at the lowest voltage limitincreased by 0.1 V.

A.5 Test methods for the effect of voltagevariations of the power source on theresult of the blood pressuremeasurement

A.5.1 Internal electrical power source

A.5.1.1 Apparatus

• adjustable direct current voltage supply;

• voltmeter with an uncertainty less than 0.5 % of themeasured value;

• patient simulator (see 2.15) for the auscultatoryand/or oscillometric method, having additionaldeviations originating from the simulator of notmore than 0.27 kPa (2 mmHg) for the mean value ofthe measurements and generating signals for bloodpressure values of approximately:

- systolic: 16 kPa (120 mmHg);- diastolic: 11 kPa (80 mmHg);- pulse rate: 70 min–1 – 80 min–1.

A.5.1.2 Procedure

Replace the internal electrical power source of theblood pressure measuring system by a DC voltagesupply having an impedance which is equivalent to theimpedance of the internal electrical power sourcespecified by the manufacturer. Devices intended to beused with consumer batteries shall be tested with animpedance of less than 1 Ω.

Control the DC voltage supply by reference to thevoltmeter.

Connect the blood pressure measuring system to thepatient simulator. Carry out the test at the maximumpermissible impedance of the internal electrical powersource.

Carry out 20 simulated blood pressure measurementsat the lowest voltage limit as determined in A.4.1.2increased by 0.1 V and at nominal voltage.


Determine the mean value (systolic and diastolic valuesseparately) of the 20 consecutive readings taken at eachvoltage level.

A.5.2 External electrical power source -alternating current

A.5.2.1 Apparatus

• adjustable alternating current voltage supply;• voltmeter with an uncertainty less than 0.5 % of the

measured value;• patient simulator as described in A.5.1.1.

A.5.2.2 Procedure

Connect the blood pressure measuring system to theAC voltage supply. Control the AC voltage supply by

OIML R 16-2: 2002 (E)

14

reference to the voltmeter. Connect the blood pressuremeasuring system to the simulator.

Carry out 20 simulated blood pressure measurementseach at:• the maximum rated voltage, declared by the manu-

facturer, increased by 10 %;• the mean value of the maximum and minimum rated

voltage, declared by the manufacturer;• the minimum rated voltage, declared by the




A.5.3 External electrical power source - direct current

A.5.3.1 Apparatus

• adjustable direct current voltage supply;• voltmeter with an uncertainty less than 0.5 % of the

measured value;• patient simulator as described in A.5.1.1.

A.5.3.2 Procedure

Connect the blood pressure measuring system to theDC voltage supply. Control the DC voltage supply byreference to the voltmeter. Connect the blood pressuremeasuring system to the simulator.

Carry out 20 simulated blood pressure measurementseach at:• the maximum rated voltage, declared by the

manufacturer, increased by 10 %;• the mean value of the maximum and minimum rated

voltage, declared by the manufacturer;• the minimum rated voltage declared by the




A.6 Method of test for air leakage of thepneumatic system

A.6.1 Apparatus

• rigid metal cylinder of an appropriate size;• pressure generator, e.g. ball pump (hand pump) with

deflation valve;• stopwatch.

A.6.2 Procedure

If because of technical reasons, the test as described inthis subclause cannot be performed, use an alternativetest procedure specified by the manufacturer.

Carry out the test at constant temperature in the range15 °C to 25 °C.

Before beginning the test, allow the blood pressuremeasuring system to reach working temperature.

Wrap the cuff around the cylinder (see 6.2) such that,for devices measuring at the upper arm and the thigh,the circumference of the applied cuff does not exceedthat of the cylinder by more than 7 %.

Note 1: Electro-mechanical pumps which are a part ofthe system may be used for the test. Valveswhich are permanently opened may bedisconnected for the test.

Note 2: For this test no calibrated reference mano-meter is required because the cuff pressuredisplay of the unit under test can be used whenthe error of the cuff pressure indication istaken into account. The advantage of this testis that the unit under test is in its originalconfiguration. Additional connections canincrease the leakage.

Carry out the test over the whole measuring range at atleast five equally spaced pressure steps (e.g. 7 kPa(50 mmHg), 13 kPa (100 mmHg), 20 kPa (150 mmHg),27 kPa (200 mmHg) and 34 kPa (250 mmHg)). Becausethe thermodynamic equilibrium is influenced bydecreasing or increasing the pressure when changingto the next pressure step, wait at least 60 s beforereading the values. Test the air leakage over a period of5 minutes and determine the measured value from this.


Express the air leakage as the rate of pressure loss perminute.

OIML R 16-2: 2002 (E)

15

A.7 Method of test for the pressurereduction rate

A.7.1 Apparatus

• T-piece connectors;• calibrated reference manometer with signal output

port and an uncertainty less than 0.1 kPa(0.8 mmHg);

• artificial or human limbs (see Notes under A.7.2);• recording unit.

A.7.2 Procedure

Measure the pressure reduction rate either on humansubjects or artificial limbs.

Note 1: The intention is to use artificial limbs, but asthese are still under consideration, measure-ments performed with human volunteers areacceptable.

Note 2: Two limb sizes should be used, being equal tothe upper and lower limits of limb circum-ferences with which a particular size of cuff isrecommended for use.

Note 3: It is intended that the characteristics of theartificial limbs reflect some elastic characteris-tics of human limbs.

Because the cuff deflation rate may be influenced bythe way that a cuff is applied, apply and remove thecuff for each of at least ten repeated measurements onat least two different limb sizes. The deflation may bereset.

Connect the calibrated reference manometer to the cuffby means of a T-piece. Connect the output part of thecalibrated reference manometer to the recording unit.


Determine the rate of pressure reduction (e.g. bygraphical evaluation and drawing tangents) at thepressure values 8 kPa (60 mmHg), 16 kPa (120 mmHg)and 24 kPa (180 mmHg). Calculate the pressurereduction rate as the mean value calculated separatelyfor the pressure values 8 kPa (60 mmHg), 16 kPa(120 mmHg) and 24 kPa (180 mmHg) and for thevarious limb circumferences.

If the pressure reduction rates are dependent on thepulse, record the pulse rate. In this case, express theresult as pressure reduction rate per pulse.

A.8 Method of test for the rapid exhaustvalve

A.8.1 Apparatus

• two rigid vessels with capacities of 100 ml ± 5 % and500 ml ± 5 %, respectively;


• T-piece connector;

• stopwatch.

A.8.2 Procedure

Carry out the test with the 500 ml vessel in place of thecuff. For blood pressure measuring systems having thecapability of measuring in a neonatal/infant mode andfor devices measuring at the wrist, carry out the testwith the 100 ml vessel in place of the cuff.

Connect the calibrated reference manometer by meansof a T-piece to the pneumatic system.

Inflate at least to the maximum pressure given in 6.5.3,wait 60 s and activate the rapid exhaust valve.

Measure the time between the pressure values specifiedin 6.5.3 using the stopwatch.


Express the results as the measured exhaust times.

A.9 Test method for the zero setting

A.9.1 Apparatus

• rigid vessel with a capacity of 500 ml ± 5 %;


• electro-mechanical pressure/suction pump;

• pressure generator, e.g. ball pump (hand pump) withdeflation valve;

• T-piece connectors;

• hoses.

OIML R 16-2: 2002 (E)

16

A.9.2 Procedure and evaluation

If, because of technical reasons, the test as described inthis subclause cannot be performed, use an alternativetest procedure specified by the manufacturer.

To test the function of the zero setting, apply a pressureof + 0.8 kPa (+ 6 mmHg) and subsequently – 0.8 kPa(– 6 mmHg) to the pneumatic system and initiate a zerosetting of the device. Ensure that all displayed pressurevalues have a systematic error of – 0.8 kPa (– 6 mmHg)and + 0.8 kPa (+ 6 mmHg), respectively.

Before beginning the test, allow the blood pressuremeasuring system to reach working temperature.

Set up the blood pressure measuring system to betested as follows:• replace the cuff with the 500 ml vessel;• insert the calibrated reference manometer into the

pneumatic system by means of a T-piece connector;• insert the pressure/suction pump into the pneumatic

system by means of a T-piece connector;• insert the pressure generator into the pneumatic

system by means of a T-piece connector.

Note: If convenient, one adjustable pump may be usedin place of the pressure/suction pump andpressure generator to generate the pressures.

Proceed in the following way:a) Initiate a zero setting as described by the

manufacturer. Set the blood pressure measuringsystem to the service mode, if available. Raise thepressure to 13 kPa (100 mmHg) immediatelyafterwards and record the displayed value.

b) Generate a constant gauge pressure of + 0.8 kPa(+ 6 mmHg) in the pneumatic system by using thepressure/suction pump at the moment of zerosetting. During this period close the deflation valveof the device under test or close the hose to it, e.g.by pinching the hose tightly. Set the blood pressuremeasuring system to the service mode, if available.Raise the pressure to 13 kPa (100 mmHg)immediately afterwards. The zero setting isoperating correctly if the displayed value decreasesby 0.8 kPa (6 mmHg) compared to the value takenin a).

c) Repeat b) with a constant gauge pressure of– 0.8 kPa (– 6 mmHg) in the pneumatic system. Setthe blood pressure measuring system to the servicemode, if available. Raise the pressure to 13 kPa(100 mmHg) immediately afterwards. The zerosetting is operating correctly if the displayed valueincreases by 0.8 kPa (6 mmHg) compared to thevalue taken in a).

A.10 Test method for the drift of the cuffpressure indication

A.10.1 General

This test applies for devices performing zero settingonly immediately after switching on.

A.10.2 Apparatus

• rigid vessel with a capacity of 500 ml ± 5 %;• calibrated reference manometer with an uncertainty

less than 0.1 kPa (0.8 mmHg);• stopwatch;• T-piece connectors;• patient simulator as described in A.5.1.1.


Replace the cuff with the 500 ml vessel. Insert thecalibrated reference manometer and the patientsimulator into the pneumatic circuit by means of T-piece connectors.

Before beginning the test, allow the blood pressuremeasuring system to reach operating temperature asdescribed in the instructions for use.

Test the stability of the cuff pressure indication afterthe zero setting at a pressure value of 7 kPa (50 mmHg)according to the procedure specified in A.2.

Under the same environmental conditions determinethe time (t1) until the change of the cuff pressureindication exceeds 0.1 kPa (1 mmHg). Switch off thedevice and switch on afterwards. Perform one bloodpressure measurement and wait until the device hasswitched off automatically. Determine the time (t2)between switching on and automatically switching off.The time (t2) shall be less than or equal to the time (t1).

A.11 Test method for the stability of theblood pressure determination(influence of temperature andhumidity)

A.11.1 Apparatus

• patient simulator as described in A.5.1.1;

OIML R 16-2: 2002 (E)

17

• climatic chamber, capable of adjustment to anaccuracy of 1 °C for the temperature and 5 % for therelative humidity.

A.11.2 Procedure

Carry out the testing of the signal processing by meansof the patient simulator. For each of the followingcombinations of temperature and humidity, place theblood pressure measuring system for at least 3 h in theclimatic chamber to allow the system to reach steadyconditions:• 10 °C ambient temperature, 85 % relative humidity



(non-condensing).

For each combination of temperature and humidity,take 20 consecutive readings of the blood pressuremeasuring system under test.

Place the blood pressure measuring system in theclimatic chamber for at least 3 h. At each combinationof temperature and humidity switch on the bloodpressure measuring system before starting the test.Wait until the warm up time (described in theinstructions for use) has elapsed, carry out themeasurement (20 consecutive readings) and switch offthe blood pressure measuring system afterwards.


Determine the mean value (systolic and diastolic valuesseparately) of the 20 consecutive readings taken at eachcombination of temperature and humidity.

Note: Because the testing of the influence oftemperature and humidity for the signalprocessing cannot be separated from thetemperature/humidity effect on the pressuretransducer and the deviations originating fromthe simulator, both contributions should betaken into account for the evaluation of the test.

A.12 Test method for the stability of cuffpressure indication followingprolonged usage

A.12.1 Procedure

Carry out the test according to the procedure specifiedin A.2 prior to prolonged usage.

Perform 10 000 simulated measurement cycles with thecomplete blood pressure measurement system at whichat least the following cuff pressure values shall bereached:• adult mode: 20 kPa (150 mmHg);• neonatal/infant mode: 10 kPa (75 mmHg).

Note 1: For devices which measure with the ausculta-tory and oscillometric method this test shouldbe carried out for both modes.

Note 2: For devices which measure in both modes(adult and neonatal/infant) the test should becarried out in both modes.


Express the result as the difference between the cuffpressure indication before and after 10 000 simulatedblood pressure measurement cycles at the same testpressure and under the same environmental condi-tions.

A.13 Test method for the effect of externalvoltages and abnormal connections tothe signal input/output ports

A.13.1 Apparatus

• rigid vessel with a capacity of 500 ml ± 5 %;• calibrated reference manometer with an uncertainty

less than 0.1 kPa (0.8 mmHg);• T-piece connectors;• pressure generator, e.g. ball pump (hand pump) with

deflation valve.

A.13.2 Procedure

Replace the cuff with the 500 ml vessel, insert thecalibrated reference manometer into the pneumaticsystem by means of a T-piece and proceed as follows.

a) Raise the pressure to 13 kPa (100 mmHg) andrecord the displayed value.

b) Repeat a) whilst short circuiting all contacts of thesignal input/output ports belonging to the non-invasive blood pressure measuring system.

c) Repeat a) whilst applying the maximum voltagespecified by the manufacturer (see 7.5) to eachcontact belonging to the non-invasive bloodpressure measuring system.

OIML R 16-2: 2002 (E)

18

A.13.3 Evaluation

Compare the indicated value under a) with theindicated values under b) and c).

A.14 Test method for the cuff pressuredeflation following an abortedmeasurement

A.14.1 Apparatus


• T-piece connectors.


Insert the calibrated reference manometer into thepneumatic system by means of a T-piece.

Start a blood pressure measurement. Abort the meas-urement during inflation. Start another measurementand abort it during the pressure reduction. If intervalmeasurements are possible repeat the test in this mode.

Check by visual inspection whether the rapid exhaust(6.5.3) is activated.

OIML R 16-2: 2002 (E)

19

Explanatory notes on the test report format

i) General

This Test report format, which is informative with regard to the implementation of OIML Recommendation R 16-2in national regulations, presents a standardized format for the results of the various tests and examinations to whicha type of sphygmomanometer shall be submitted with a view to its approval as well as for the results of verificationtests. The tests are listed in Annex A of this International Recommendation.

It is recommended that all metrology services or laboratories evaluating types of sphygmomanometers according toOIML R 16-2 or to national or regional regulations based on OIML R 16-2 use this Test report format, directly or aftertranslation into a language other than English or French.

It is also recommended that this Test report format in English or in French (or in both languages) be transmitted bythe country performing these tests to the relevant authorities of another country, under bi- or multi-lateralcooperation agreements.

In the framework of the OIML Certificate System for Measuring Instruments, use of the Test report format ismandatory.

ii) Page numbering and the use of report page formats

In addition to the sequential numbering at the bottom of each page, a space has been left at the top of each page(starting on page 22) for numbering the pages of reports established following this model. In particular, each test isreported individually on a separate page following the relevant format.

For a given report, it is advisable to complete the sequential numbering of each page by indicating the total numberof pages in the report.

Where required, pressure values in the Tables can be replaced by values expressed in kPa.

Where required, these forms can be copied and used several times in cases where the test in question has to berepeated under varying conditions.

iii) Definitions and formula

For the purposes of this test report format, the following definitions and formula, taken from the InternationalVocabulary of Basic and General Terms in Metrology (VIM, 1993 edition) are used.

Conventional true value (of a quantity) [VIM 1.20]

value attributed to a particular quantity and accepted, sometimes by convention, as having an uncertainty appropriate for givenpurpose.

Annex B

Test Report Format

(Mandatory for application within the OIML Certificate System for Measuring Instruments)

OIML R 16-2: 2002 (E)

20

EXAMPLES

a) at a given location, the value assigned to the quantity realized by a reference standard may be taken as a conventional true value;

b) the CODATA (1986) recommended value for the Avogadro constant NA: 6,022 136 7 × 1023 mol–1.

NOTES

1 “Conventional true value” is sometimes called assigned value, best estimate of the value, conventional value or reference value.“Reference value”, in this sense, should not be confused with “reference value” in the sense used in the note to VIM 5.7.

2 Frequently, a number of results of measurements of a quantity is used to establish a conventional true value.

Experimental standard deviation [VIM 3.8]

for a series of n measurements of the same measurand, the quantity s characterizing the dispersion of the results and given by theformula:

xi being the result of the ith measurement and x– being the arithmetic mean of the n results considered.

NOTES

1 Considering the series of n values as a sample of a distribution, x– is an unbiased estimate of the mean µ, and s2 is an unbiasedestimate of the variance σ 2, of that distribution.

2 The expression s / ABn is an estimate of the standard deviation of the distribution of x– and is called the experimental standarddeviation of the mean.

3 “Experimental standard deviation of the mean“ is sometimes incorrectly called standard error of the mean.

Uncertainty of measurement [VIM 3.9]

parameter, associated with the result of a measurement, that characterizes the dispersion of the values that could reasonably beattributed to the measurand.

NOTES

1 The parameter may be, for example, a standard deviation (or a given multiple of it), or the half-width of an interval having a statedlevel of confidence.

2 Uncertainty of measurement comprises, in general, many components. Some of these components may be evaluated from thestatistical distribution of the results of series of measurements and can be characterized by experimental standard deviations. Theother components, which can also be characterized by standard deviations, are evaluated from assumed probability distributionsbased on experience or other information.

3 It is understood that the result of the measurement is the best estimate of the value of the measurand, and that all components ofuncertainty, including those arising from systematic effects, such as components associated with corrections and referencestandards, contribute to the dispersion.

This definition is that of the “Guide to the expression of uncertainty in measurement” in which its rationale is detailed (see, inparticular, 2.2.4 and annex D [10]).

s = (xi – x–)2

n – 1

Σn

i = 1ABBB

OIML R 16-2: 2002 (E)

21

Error (of measurement) [VIM 3.10)]

result of a measurement minus a true value of the measurand.

NOTES

1 Since a true value cannot be determined, in practice a conventional true value is used (see VIM 1.19 and VIM 1.20).

2 When it is necessary to distinguish “error“ from “relative error”, the former is sometimes called absolute error of measurement.This should not be confused with absolute value of error, which is the modulus of the error.

Deviation [VIM 3.11]

value minus its reference value.

Systematic error [VIM 3.14]

mean that would result from an infinite number of measurements of the same measurand carried out under repeatability conditionsminus a true value of the measurand.

NOTES

1 Systematic error is equal to error minus random error

2 Like true value, systematic error and its causes cannot be completely known.

3 For a measuring instrument, see “bias” (VIM 5.25).

Maximum permissible errors (of a measuring instrument) [VIM 5.21]

extreme values of an error permitted by specifications, regulations, etc. for a given measuring instrument.

22

TYPE APPROVAL TEST REPORT nVERIFICATION TEST REPORT n

(For verification purposes tick those fields which are appropriate for verificationaccording to your national regulations or which are listed in B.1.2

under the heading: Summary of test results for verification.)

Number of report: ....................................................

Object: ...................................................................................................................................................................................

Type: ......................................................................................................................................................................................

Serial number: ......................................................................................................................................................................

Manufacturer’s name and address: .....................................................................................................................................

................................................................................................................................................................................................

................................................................................................................................................................................................

Customer’s name and address: ............................................................................................................................................

................................................................................................................................................................................................

................................................................................................................................................................................................

Date of receipt: .....................................................................................................................................................................

Date/period of measurement: ..............................................................................................................................................

Date of report: .................................................................. Number of pages: ...................................................................

Issuing Institute’s name and address: .................................................................................................................................

................................................................................................................................................................................................

................................................................................................................................................................................................

Characteristic values (principle of measurement, measuring unit, measuring range, range of display): ...................................................................................................................................

................................................................................................................................................................................................

Additional devices (printer, interface etc.): ........................................................................................................................

................................................................................................................................................................................................

Reference manometer (serial number, uncertainty, calibration certificate): ...................................................................

................................................................................................................................................................................................

Stamp/signature:

Report page ..../.... OIML R 16-2: 2002 (E)

Non-invasive automated sphygmomanometersOIML R 16-2 Edition 2002 (E)

TEST REPORT

23

B.1 Test review

B.1.1 Summary of test results for type approval

OIML R 16-2: 2002 (E) Report page ..../....

Clause Subject Maximum Maximum Passed Faileddeviation permissible error

B.2 Cuff pressure indication

B.3 Effect of temperature on cuff pressure indication

B.4 Effect of voltage variations of the power source

B.4.1 Internal electrical power source

B.4.2 External electrical power source

B.5 Environmental performance

B.5.1 Effect of storage on cuff pressure indication

B.5.2 Electromagnetic interferences

Normal operation again, when?

B.6 Air leakage rate

B.7 Pressure reducing system

B.8 Rapid exhaust

B.9 Zero setting

B.10 Stability of the cuff pressure indication

B.11 Pressure indicating device

B.11.1 Nominal range and measuring range

B.11.2 Digital indication

B.12 Signal input and output ports

B.13 Maximum permissible error of the overall system

B.13.1 Maximum mean error

B.13.2 Maximum experimental standard deviation

B.14 Alarms

B.15 Safety

B.15.1 Electrical safety

B.15.2 Resistance to vibration and shock

B.15.3 Cuff pressure

B.15.4 Unauthorized access

B.15.5 Tubing connectors

B.16 Tamper proofing

24

B.1.2 Summary of test results for verification

Note 1: The sequence of the different tests is arbitrary; it follows the sequence of the different clauses in the text.The sequence of testing is at the discretion of the person conducting the tests.

Note 2: To be considered as approved or verified, an instrument must have successfully passed all the applicabletests.

B.2 Maximum permissible errors of the cuff pressure indication

For the limits of temperature and humidity see 5.1: the temperature should be between 15 °C and 25 °C, the relativehumidity should be between 20 % and 85 %.

To find out the error of the cuff pressure indication proceed as follows (up and down runs) at three differenttemperatures: e.g. 15 °C and 20 % relative humidity, 20 °C and 60 % relative humidity and 25 °C and 85 % relativehumidity.

Table 1 Example: Temperature 20 °C and …. % relative humidity

Maximum deviation: 5 mmHg




B.6 Air leakage rate

B.15 Safety




B.15.5.1 Regular use

B.15.5.2 Warning in the manual


pressure 1st reading 2nd reading mean deviation

mmHg up down up down up down up down

0 2 0 0 4 1 2 1 2

50 52 54 54 54 53 54 3 4

100 106 100 104 104 105 102 5 2

150

200

250

column 1 column 2 column 3 column 4 column 5 column 6 column 7 column 8 column 9

25

Column 1 = values measured by the reference manometer

Column 2, 3, 4 and 5 = results of the measurement of the instrument under test

Column 6 = (column 2 + column 4) / 2


Column 8 = column 6 – column 1


Table 2 Temperature ….. °C and ..... % relative humidity

Maximum deviation: .............

Note: The time between up and down run should not be less than 5 minutes at the maximum pressure. A timedifference from the first run to the second run of one hour is recommended.

Is the maximum deviation of all of the readings of the instrument under test and of the reference manometer lessthan or equal to ± 0.4 kPa (± 3 mmHg) for type approval test and first verification and less than or equal to ± 0.5 kPa(± 4 mmHg) for subsequent verification, respectively (see 5.1)?

yes n D passed n

no n D failed n


pressure 1st reading 2nd reading mean deviation


0

50

100

150

200

250

300 or max

26


Refer to A.3.

Note 1: For a type approval test report testing has to be carried out also at 10 °C and 40 °C (see A.3.2.1, A.3.2.2,A.3.2.3).

Note 2: Take the first mean of the readings of the measuring instrument before storage as reference value (Table 2)and calculate the deviation of the mean of the values measured after storage (mean values here in Table 3)from the mean values of Table 2. The result should be within the error limits mentioned below.

For each of the following combinations of temperature and humidity, condition the device for at least 3 h in theclimatic chamber (see A.3.1) to allow the device to reach steady conditions.

Table 3 Temperature 10 °C and 85 % relative humidity




Is the maximum deviation of all of the readings of the instrument under test and the reference manometer less thanor equal to ± 0.4 kPa (± 3 mmHg) (see 5.3.2)?

yes n D passed n

no n D failed n


pressure1st reading 2nd reading mean


0

50

100

150

200

250

300 or max

deviation from Table 2



0

50

100

150

200

250

300 or max


27

B.4 Effect of voltage variations of the power source

B.4.1 Internal electrical power source

For reference see A.5.1.

Do the changes of voltage within the working range of the internal power source influence the result of the bloodpressure measurement in such a way that the results of the blood pressure measurement deviate more than themaximum permissible error (MPE, see 5.2) from the values of a measurement by the reference manometer?

yes n D failed n

no n D passed n

Note: Outside this working range no cuff pressure reading and no result of the blood pressure measurement shallbe displayed.

Does a change of voltage outside of the working range of the internal power source lead to a result of a bloodpressure measurement?

yes n D failed n

no n D passed n

Testing should be carried out in accordance with A.4.1 and A.5.1.

B.4.2 External electrical power source

For reference see A.5.2 and A.5.3.

Do the changes of voltage within the working range of the external power source influence the result of the bloodpressure measurement in such a way that the results of the blood pressure measurement deviate more than themaximum permissible error (MPE, see 5.2) from the values of a measurement by the reference manometer?

yes n D failed n

no n D passed n

Testing should be carried out in accordance with A.4.2 and A.5.2 (alternating current) or A.4.3 and A.5.3 (directcurrent).

Note: Incorrect values resulting from voltage variations outside the limits given above shall not be displayed.

Does a change of voltage outside of the working range of the external power source lead to a result of a bloodpressure measurement?

yes n D failed n

no n D passed n

Testing shall be carried out according to Annex A.4.4 (alternating current) and A.4.5 (direct current).


28

B.5 Environmental performance

B.5.1 Storage

Determine the error after the storage for 24 h at a temperature of – 5 °C and for 24 h at a temperature of 50 °C anda relative humidity of 85 %.

Table 5 Measurement at 20 °C and 60 % relative humidity after storage at – 5 °C and 50 °C


Refer to 5.3.1. and A.2.

Is the maximum deviation of the cuff pressure indication (mean value), after storage at – 5 °C and 50 °C, less thanor equal to ± 0.4 kPa (± 3 mmHg) compared to the mean values at 20 °C and 60 % relative humidity before storage?

yes n D passed n

no n D failed n

Note: Integrated multiparameter monitors may contain components which may be damaged during storage. Thegeneral temperature range has therefore been reduced.

B.5.2 Electromagnetic compatibility

Do electrical and/or electromagnetic interferences lead to degradations in the cuff pressure indication or in theresult of the blood pressure measurement?

yes n D failed n

no n D passed n




0

50

100

150

200

250

300 or max


29

If electrical and/or electromagnetic interferences lead to an abnormality, is the abnormality clearly indicated and isit possible to restore normal operation within 30 s after cessation of the electromagnetic disturbance?

yes n D passed n

no n D failed n

Testing should be carried out in accordance with OIML D11.

B.6 Air leakage rate of the pneumatic system

Carry out the test over the whole measuring range at five equally spaced pressure steps at least (e.g. 7 kPa(50 mmHg), 13 kPa (100 mmHg), 20 kPa (150 mmHg), 27 kPa (200 mmHg) and 33 kPa (250 mmHg)). Test the airleakage rate over a period of 5 min (see A.6.2) and determine the measured value from this. Wait at least 60 s beforereading each value.

Table 6

Does the air leakage rate over a period of 5 minutes correspond to a pressure drop less than or equal to 0.8 kPa/min(6 mmHg/min)?

yes n D passed n

no n D failed n

B.7 Pressure reducing system for devices using the auscultatory method

Is the deflation rate of 0.3 kPa/s to 0.4 kPa/s (2 mmHg/s to 3 mmHg/s) within the target range of systolic anddiastolic blood pressure maintained?

yes n D passed n

no n D failed n


pressure first reading reading after 5 min difference between the readings

50 mmHg

100 mmHg

150 mmHg

200 mmHg

250 mmHg

30

For devices which control the pressure reduction as a function of the pulse rate:

Is a deflation rate of 0.3 kPa/pulse and 0.4 kPa/pulse (2 mmHg/pulse and 3 mmHg/pulse) maintained?

yes n D passed n

no n D failed n

Note: Manually operated deflation valves should be easily adjustable to these values.


B.8 Rapid exhaust

Does the time for the pressure reduction from 35 kPa to 2 kPa (260 mmHg to 15 mmHg) during the rapid exhaustof the pneumatic system with the valve fully opened exceed 10 s?

yes n D failed n

no n D passed n

For blood pressure measuring systems, having the capability to measure in a neonatal/infant mode:

Does the time for the pressure reduction from 20 kPa to 0.7 kPa (150 mmHg to 5 mmHg) during the rapid exhaustof the pneumatic system with the valve fully opened exceed 5 s?

yes n D failed n

no n D passed n


B.9 Zero setting

Blood pressure measuring systems shall be capable of automatic zero setting. The zero setting shall be carried outat appropriate intervals, at least starting after switching on the device. At the moment of the zero setting a gaugepressure of 0 kPa (0 mmHg) shall exist and be displayed thereafter.

Do devices performing zero setting only immediately after switching on, switch off automatically when the drift ofthe pressure transducer and the analog signal processing exceeds 0.1 kPa (1 mmHg)?

yes n D passed n

no n D failed n


31

At the moment of the zero setting does a gauge pressure of 0 kPa (0 mmHg) exist and is it displayed?

yes n D passed n

no n D failed n

Testing shall be carried out in accordance with A.9 and A.10.

B.10 Stability of the cuff pressure indication

Is the change of the cuff pressure indication less than 0.4 kPa (3 mmHg) throughout the pressure range after 10 000simulated measurement cycles?

yes n D passed n

no n D failed n

Testing shall be carried out in accordance with 6.7 and A.12.



The nominal range for the cuff pressure measurement shall be specified by the manufacturer. The measuring andindication ranges of the cuff pressure shall be equal to the nominal range.

Are values of blood pressure measurement results outside the nominal range of cuff pressure clearly indicated asout of range?

yes n D passed n

no n D failed n


B.11.2 Digital indication

Is the digital scale interval 0.1 kPa (1 mmHg)?

yes n D passed n

no n D failed n


32

Note 1: If the measured value of a parameter is to be indicated on more than one display, all the displays shallindicate the same numerical value.

Note 2: Measured numerical values on the display(s), and the symbols defining the units of measurement shall bearranged in such a way so as to avoid misinterpretation.

Note 3: Numbers and characters should be clearly legible.

Testing shall be carried out by visual inspection. For reference see 6.8.

B.12 Signal input and output ports

Note: The construction of the signal input and output ports (excluding internal interfaces, e.g. microphone signalinput) relevant to the non-invasive blood pressure measurement shall ensure that incorrectly fitted ordefective accessories shall not result in erroneous indication of cuff pressure or erroneous indication of bloodpressure.


For reference see 6.9.

Does the construction of the signal input and output ports (excluding internal interfaces, e.g. microphone signalinput) ensure that incorrectly fitted or defective accessories relevant to the non-invasive blood pressure measure-ment do not result in erroneous indication of cuff pressure or erroneous indication of blood pressure?

yes n D passed n

no n D failed n

An erroneous indication is an indication with an error bigger than the MPE.

B.13 Maximum permissible error of the overall system as measured by clinical tests

The error of each measurement is to be calculated according to definition 3.10 of the VIM (see paragraph iii of theexplanatory notes at the beginning of Annex B). The reference values are derived from the conventional measure-ment carried out by a medical doctor using a mechanical sphygmomanometer and the Korotkoff method. Usuallya set of at least 3 measurements per patient has to be carried out. Having one instrument under test, a sample of atleast 85 persons and at least 2 medical doctors should be involved in the tests.

The mean of the errors measured within each set of measurements has to be calculated and the maximum of thesemean errors relating to the sets of measurement of the different patients has to be determined. Refer also to C.3(AAMI/ANSI SP10, 1992 and Amendment 1996).

B.13.1 Maximum mean error

Is the maximum mean error obtained by the clinical tests less than or equal to ± 0.7 kPa (± 5 mmHg)?

yes n D passed n

no n D failed n

For reference see 5.2.1.


33

B.13.2 Maximum experimental standard deviation

Is the maximum experimental standard deviation less than or equal to 1.1 kPa (8 mmHg)?

yes n D passed n

no n D failed n

For reference see 5.2.2. For definitions see paragraph iii of the explanatory notes at the beginning of Annex B.

B.14 Alarms

Note: If alarms are used they shall be of at least medium priority.

The alarms are of acoustic nature and can be delivered with different volume, frequencies and even differentmelodical patterns. Different alarms are correlated to different events. These alarms/events have different priorities.A low level priority could indicate e.g. beginning of problems with the battery, highest priority would be reservedfor an alarm indicating a situation which is dangerous for the life of the patient.

For reference see 6.10.

B.15 Safety

B.15.1 Electrical safety (This test is optional within the OIML Certificate System)

Refer to 6.11.4.

Are the requirements of the regional and national regulations fulfilled?

yes n D passed n

no n D failed n

B.15.2 Resistance to vibration and shock

Refer to 6.11.5.

The mechanical conditions can be found in OIML D 11 (e.g. subclause A.2.2 of the 1994 edition).

Are the requirements according to OIML D 11 fulfilled?

yes n D passed n

no n D failed n


34


Note: It shall be possible to abort any blood pressure measurement at any time by single key operation and thisshall lead to a rapid exhaust (see B.8).


Is it possible to abort any blood pressure measurement at any time by single key operation and does this lead to arapid exhaust (see B.8)?

yes n D passed n

no n D failed n


Are all controls which affect accuracy sealed against unauthorized access?

yes n D passed n

no n D failed n

Note: Controls are any part of the instrument which can be used for adjusting the measurement values, thesubsequent computation and the display, including adjusting screws, potentiometers, adjusting modules,pressure sensing devices, etc.




Note: Users of equipment intended for use in environments employing intervascular fluid systems shall take allnecessary precautions to avoid connecting the output of the blood pressure measuring device to such systemsas air might inadvertently be pumped into a blood vessel if, for example, Luer locks were used1.

For reference see 6.11.3 and 7.5.

B.15.5.1

Are Luer locks used?

yes n D failed n

no n D passed n


1 Luer lock connectors shall not be used with the tubing which connects the cuff to the manometer or measuring equipment, in order toavoid the possibility of inadvertent misconnection with other clinical systems.

35

B.15.5.2

Is the warning (see Note above and 7.5) mentioned in the instruction manual?

yes n D passed n

no n D failed n


Is the manometer tamper proof?

yes n D passed n

no n D failed n

Tamper proofing of the instrument shall be achieved by requiring the use of a tool or breaking a seal.



OIML R 16-2: 2002 (E)

Annex C

Rationale for the maximum permissible errors of the overall system

(Informative)

Note: This Annex provides a rationale for the values of maximum permissible errors presented in 5.2.

Overall system accuracy

A clinical investigation is strongly recommended to demonstrate compliance with the requirements specified in 5.2.A new clinical investigation would be necessary only for changes affecting the overall system accuracy.

Recommended protocols for the clinical investigations are given in:

C.1 O’Brien E., Petrie J., Littler W., de Swiet M., Padfield P.L., Altman D.G., Bland M., Coats A. and Atkins N. TheBritish Hypertension Society protocol for the evaluation of blood measuring devices. Journal of Hypertension1993, 11 (Suppl 2): S 43 - 62

C.2 E DIN 58130: 1995, Non-invasive sphygmomanometers - Clinical investigation

C.3 AAMI/ANSI SP10, American National Standard for electronic or automated sphygmomanometers, 1992, andAmendment, 1996

Printed in France GRANDE IMPRIMERIE DE TROYES

Non-invasive mechanical sphygmomanometers

Sphygmomanomètres non invasifs mécaniques

OIM

L R

16-

1 Ed

ition

2002

(E)

OIML R 16-1Edition 2002 (E)

ORGANISATION INTERNATIONALE

DE MÉTROLOGIE LÉGALE

INTERNATIONAL ORGANIZATION

OF LEGAL METROLOGY

INTERNATIONAL

RECOMMENDATION

OIML R 16-1: 2002 (E)

2

Contents

Foreword ........................................................................................................................................................................... 3

1 Scope ........................................................................................................................................................................... 4

2 Terminology ................................................................................................................................................................ 4

3 Description of the category of instrument ................................................................................................................ 5

4 Units of measurement ................................................................................................................................................ 5

5 Metrological requirements ......................................................................................................................................... 5

6 Technical requirements .............................................................................................................................................. 6

7 Metrological controls ................................................................................................................................................. 8

Annex A: Test procedures (Mandatory) ....................................................................................................................... 10

Annex B: Test report format (Mandatory for application within the OIML Certificate System for Measuring Instruments) ................................................................................. 15

Annex C: Advice to be included in the instructions accompanying a sphygmomanometer using a mercury manometer (Informative) ............................................................. 31

OIML R 16-1: 2002 (E)

3

The International Organization of Legal Metrology(OIML) is a worldwide, intergovernmental organizationwhose primary aim is to harmonize the regulations and

metrological controls applied by the national metrologicalservices, or related organizations, of its Member States.

The two main categories of OIML publications are:

• International Recommendations (OIML R), which aremodel regulations that establish the metrological charac-teristics required of certain measuring instruments andwhich specify methods and equipment for checking theirconformity; the OIML Member States shall implementthese Recommendations to the greatest possible extent;

• International Documents (OIML D), which are inform-ative in nature and intended to improve the work of themetrological services.

OIML Draft Recommendations and Documents are devel-oped by technical committees or subcommittees which areformed by the Member States. Certain international andregional institutions also participate on a consultation basis.

Cooperative agreements are established between OIML andcertain institutions, such as ISO and IEC, with the objectiveof avoiding contradictory requirements; consequently, manu-facturers and users of measuring instruments, test labor-

atories, etc. may apply simultaneously OIML publicationsand those of other institutions.

International Recommendations and International Docu-ments are published in French (F) and English (E) and aresubject to periodic revision.

This publication - reference OIML R 16-1 Edition 2002 - wasdeveloped by the OIML Technical Subcommittee TC 18/SC 1Blood pressure instruments. This publication was approvedfor final publication by the International Committee of LegalMetrology in 2001 and will be submitted to the InternationalConference of Legal Metrology in 2004 for formal sanction.

OIML Recommendation R 16 includes two parts: Part 1(Non-invasive mechanical sphygmomanometers) and Part 2(Non-invasive automated sphygmomanometers) which havebeen issued in 2002 as separate publications. It supersedesthe former editions dated 1973 (English version) and 1970(French version).

OIML publications may be obtained from the Organization’sheadquarters:

Bureau International de Métrologie Légale11, rue Turgot - 75009 Paris - FranceTelephone: 33 (0)1 48 78 12 82 and 42 85 27 11Fax: 33 (0)1 42 82 17 27E-mail: [email protected]: www.oiml.org

Foreword

OIML R 16-1: 2002 (E)

4

1 Scope

This Recommendation specifies general, performance,efficiency and mechanical and electrical safety require-ments, including test methods for type approval, fornon-invasive mechanical sphygmomanometers andtheir accessories which, by means of an inflatable cuff,are used for the non-invasive measurement of arterialblood pressure. The application of the cuff is notlimited to a particular extremity of the human body(e.g. the upper arm).

Included within the scope of this Recommendation aresphygmomanometers with a mechanical pressuresensing element and display, used in conjunction witha stethoscope or other manual methods for detectingKorotkoff sounds and for cuff inflation.

Note: Luer locks shall not be used with these devices(see 7.5).

2 Terminology

2.1 Bladder

Inflatable component of the cuff.

2.2 Pressure in a blood vessel

Pressure in the arterial system of the body.

2.3 Cuff

Component of the sphygmomanometer, comprising abladder and a sleeve, which is wrapped around thelimb of the patient.

2.4 Diastolic blood pressure (value)

Minimum value of the arterial blood pressure as aresult of relaxation of the systemic ventricle.


2.5 Mean arterial blood pressure (value)

Value of the integral of one cycle of the blood pressurecurve divided by the time of one heart beat period.


2.6 Non-invasive blood pressure measurement

Indirect measurement of the arterial blood pressurewithout arterial puncture.


System that includes all pressurized and pressure-controlling parts such as cuff, tubing, connectors,valves, transducer and pump.

2.8 Sleeve

Essentially inelastic part of the cuff that encloses thebladder.

2.9 Sphygmomanometer

Instrument used for the non-invasive measurement ofthe arterial blood pressure.

2.10 Systolic blood pressure (value)

Maximum value of the arterial blood pressure as aresult of the contraction of the systemic ventricle.

Non-invasive mechanical sphygmomanometers

OIML R 16-1: 2002 (E)

5


2.11 Mechanical sphygmomanometer

Sphygmomanometer which uses either a mercury oran aneroid manometer or another mechanical measur-ing device for the non-invasive measurement of thearterial blood pressure by means of an inflatable cuff.(See also Note under 3.)

2.12 Auscultatory method

Technique whereby sounds (known as Korotkoffsounds) are heard over an occluded artery as theoccluding pressure is slowly released, the appearanceof sounds coinciding with the systolic blood pressureand the disappearance of sounds with the diastolicblood pressure in adults. In children under age of 13,“k4” (i.e. 4th phase Korotkoff sound) may be appro-priate.

2.13 Deflation valve

Valve for controlled exhaust of the pneumatic systemduring measurement.

2.14 Rapid exhaust valve

Valve for rapidly exhausting the pneumatic system.

2.15 Tamper proofing

Means of preventing the user from gaining easy accessto the measuring mechanism of the device.

3 Description of the category of instrument

The basic components of a sphygmomanometer are acuff and bladder that can be wrapped around a patient’slimb, a manual system for applying and releasingpressure to the bladder, and a means of measuring anddisplaying the instantaneous pressure in the bladder.

Mechanical sphygmomanometers typically use either amercury or an aneroid manometer or anothermechanical measuring device for the non-invasivemeasurement of the arterial blood pressure by meansof an inflatable cuff.

Note: Components of these devices are manometer,cuff, valve for deflation (often in combinationwith rapid exhaust valve), hand pump or electro-mechanical pump and connection hoses. Thesedevices may also contain electro-mechanicalcomponents for pressure control.

4 Units of measurement

The blood pressure shall be indicated either in kilo-pascals (kPa) or in millimeters of mercury (mmHg).

5 Metrological requirements

5.1 Maximum permissible errors of the cuffpressure indication

5.1.1 Under ambient conditions

For any set of conditions within the ambienttemperature range of 15 °C to 25 °C and the relativehumidity range of 20 % to 85 %, both for increasingand for decreasing pressure, the maximum permissibleerror for the measurement of the cuff pressure at anypoint of the scale range shall be ± 0.4 kPa (± 3 mmHg)in case of verifying the first time and ± 0.5 kPa(± 4 mmHg) for sphygmomanometers in use.


5.1.2 Under storage conditions

The sphygmomanometer shall maintain the maximumpermissible error requirements specified in thisRecommendation (5.1.1) after storage for 24 h at atemperature of – 20 °C and for 24 h at a temperature of70 °C and a relative humidity of 85 % (non-condens-ing).


5.1.3 Under varying temperature conditions

For the ambient temperature range of 10 °C to 40 °Cand the relative humidity of 85 % (non-condensing),

OIML R 16-1: 2002 (E)

6

the difference of the cuff pressure indication of thesphygmomanometer shall not exceed ± 0.4 kPa(± 3 mmHg).


6 Technical requirements

6.1 Technical requirements for the cuff and bladder

The cuff shall contain a bladder. For reusable cuffs themanufacturer shall indicate the method for cleaning inthe accompanying documents (see 7.5).

Note: The optimum bladder size is one with dimen-sions such that its width is 40 % of the limbcircumference at the midpoint of the cuffapplication, and its length is at least 80 %,preferably 100 %, of the limb circumference atthe midpoint of cuff application. Use of thewrong size can affect the accuracy of the meas-urement.

6.2 Technical requirements for the pneumaticsystem

6.2.1 Air leakage

Air leakage shall not exceed a pressure drop of0.5 kPa/min (4 mmHg/min).


6.2.2 Pressure reduction rate

Manually operated deflation valves shall be capable ofadjustment to a deflation rate from 0.3 kPa/s to0.4 kPa/s (2 mmHg/s to 3 mmHg/s).

Manually operated deflation valves shall be easilyadjusted to these values.

Deflation valves shall be tested in accordance with A.5.

6.2.3 Rapid exhaust

During the rapid exhaust of the pneumatic system,with the valve fully opened, the time for the pressurereduction from 35 kPa to 2 kPa (260 mmHg to15 mmHg) shall not exceed 10 s.


6.3 Technical requirements for the pressureindicating devices

6.3.1 Nominal range and measuring range

The nominal range shall be equal to the measuringrange.

The nominal range for the cuff gauge pressure shallextend from 0 kPa to at least 35 kPa (0 mmHg to atleast 260 mmHg).

6.3.2 Analogue indication

6.3.2.1 Scale

The scale shall be designed and arranged so that themeasuring values can be read clearly and are easilyrecognized.


6.3.2.2 First scale mark

The graduation shall begin with the first scale mark at0 kPa (0 mmHg).


6.3.2.3 Scale interval

The scale interval shall be:

• 0.2 kPa for a scale graduated in kPa; or• 2 mmHg for a scale graduated in mmHg.

Each fifth scale mark shall be indicated by greaterlength and each tenth scale mark shall be numbered.An example of a scale in mmHg is given in Figure 1.


6.3.2.4 Scale spacing and thickness of the scale marks

The distance between adjacent scale marks shall be notless than 1.0 mm. The thickness of the scale marksshall not exceed 20 % of the smallest scale spacing.

All scale marks shall be of equal thickness.


OIML R 16-1: 2002 (E)

7

6.4 Additional technical requirements formercury manometers

6.4.1 Internal diameter of the tube containing mercury

The nominal internal diameter of the mercury tubeshall be at least 3.5 mm. The tolerance on diametershall not exceed ± 0.2 mm (see also 7.4).


6.4.2 Portable devices

A portable device shall be provided with an adjusting orlocking mechanism to secure it in the specified positionof use.


6.4.3 Devices to prevent mercury from being spilledduring use and transport

A device shall be placed in the tube to prevent mercuryfrom being spilled during use and transport (forexample: stopping device, locking device, etc.). Thisdevice shall be such that when the pressure in thesystem drops rapidly from 27 kPa to 0 kPa (from

200 mmHg to 0 mmHg), the time taken for themercury column to fall from 27 kPa to 5 kPa (from200 mmHg to 40 mmHg) shall not exceed 1.5 s. Thistime is known as the “exhaust time”.


6.4.4 Quality of the mercury

6.4.4.1 The mercury shall have a purity of not less than99.99 % according to the declaration of the supplier ofthe mercury.

6.4.4.2 The mercury shall exhibit a clean meniscus andshall not contain air bubbles.

6.4.5 Graduation of the mercury tube

Graduations shall be permanently marked on the tubecontaining mercury.

If numbered at each fifth scale mark, the numberingshall be alternately on the right- and left-hand side of,and adjacent to, the tube.


Figure 1 Example of an aneroid manometer scale (division in mmHg without a tolerance zone at zero)

0

mmHg

20

40

60

80

100120

140 160180

200

220

240

260

280

300

OIML R 16-1: 2002 (E)

8

6.5 Additional technical requirements foraneroid manometers

6.5.1 Scale mark at zero

If a tolerance zone is shown at zero it shall not exceed± 0.4 kPa (± 3 mmHg) and shall be clearly marked.

A scale mark at zero shall be indicated.

Note: Graduations within the tolerance zone areoptional.


6.5.2 Zero

The movement of the elastic sensing element includingthe pointer shall not be obstructed within 0.8 kPa(6 mmHg) below zero.

Neither the dial nor the pointer shall be adjustable bythe user.


6.5.3 Pointer

The pointer shall cover between 1/3 and 2/3 of thelength of the shortest scale mark of the scale. At theplace of indication it shall be not thicker than the scalemark. The distance between the pointer and the dialshall not exceed 2 mm.


6.5.4 Hysteresis error

The hysteresis error throughout the pressure rangeshall be within the range 0 kPa to 0.5 kPa (0 mmHg to4 mmHg).


6.5.5 Construction and materials

The construction of the aneroid manometer and thematerial for the elastic sensing elements shall ensurean adequate stability of the measurement. The elasticsensing elements shall be aged with respect to pressureand temperature.

After 10 000 alternating pressure cycles the change inthe pressure indication of the aneroid manometer shallbe not more than 0.4 kPa (3 mmHg) throughout thepressure range.


6.6 Safety requirements

6.6.1 Resistance to vibration and shock

The sphygmomanometer shall comply with therelevant paragraphs of International Document OIMLD 11 (e.g. subclause A.2.2 of the 1994 edition for mech-anical shock).

After testing, the device shall comply with therequirements of 5.1.1 (of this Recommendation).

6.6.2 Mechanical safety

It shall be possible to abort the blood pressure meas-urement at any time by activating the manual rapidexhaust valve, which shall be easily accessible.

6.6.3 Tamper proofing

Tamper proofing of the manometer shall be achievedby requiring the use of a tool or breaking a seal.


6.6.4 Electrical safety

Regional or national regulations may specify electricalsafety requirements.

7 Metrological controls

Regional or national regulations may prescribe typeapproval, initial and/or periodic verification for non-invasive sphygmomanometers. These controls shallmeet the following conditions.

7.1 Type approval

At least three samples of a new type of sphygmo-manometer shall be tested.

The tests to verify conformity to metrological andtechnical requirements shall be carried out accordingto Annex A. A test report shall be prepared according toAnnex B.

OIML R 16-1: 2002 (E)

9

7.2 Verification

7.2.1 Initial verification

At initial verification the requirements of 5.1.1, 6.2.1and 6.4.4 shall be fulfilled.

Testing shall be carried out according to A.1, A.4 andA.11.

7.2.2 Subsequent verification

Each instrument of an approved type of sphygmo-manometer shall be verified every 2 years or afterrepair. At least 5.1.1 shall be fulfilled and tests must becarried out according to A.1.

7.3 Sealing

7.3.1 Control marks will be put on lead seals for whichcorresponding punched screws shall be attachedwhenever necessary. These seals shall prevent, withoutdestruction of the control marks:

• in the case of mercury manometers: the separation ofreservoir and scale;

• in the case of all other manometers: the opening ofthe casing.

7.3.2 If the construction of the instrument guaranteessecurity against any interference, the metrologicalcontrol marks or the security marks may be attached inform of labels.

7.3.3 All seals shall be accessible without using a tool.

7.4 Marking of the device

The device shall be marked with the following informa-tion:

• name and/or trademark of manufacturer;• serial number and year of fabrication;• measuring range and measuring unit;

• type approval number (if applicable);• center of the bladder, indicating the correct position

for the cuff over the artery; and• marking on the cuff indicating the limb circum-

ference for which it is appropriate (see 6.1).

The following additional markings are required formercury manometers:

• symbol for “see instructions for use”;• indication of the internal nominal diameter and the

tolerance of the tube containing mercury (see 6.4.1).

7.5 Manufacturer’s information

Information supplied by the manufacturer shallcomply with the specifications and requirements givenin this Recommendation.

The manufacturer’s instruction manual shall containthe following information:

• reference to OIML R 16-1, including the completetitle;

• explanation of the operating procedures which areimportant for correct application (such as the selec-tion of the appropriate cuff size, positioning of thecuff and adjustment of the pressure reduction rate);

• a warning to users of equipment intended for use inenvironments employing intervascular fluid systemsnot to connect the output of the blood pressuremeasuring device to such systems as air mightinadvertently be pumped into a blood vessel if, forexample, Luer locks were used;

• methods for cleaning reusable cuffs;• nature and frequency of the maintenance required to

ensure that the device operates correctly and safelyat all times; it is recommended that the performanceshould be checked at least every 2 years and aftermaintenance and repair, by re-verifying at least therequirements in 5.1.1, 6.2.1 (testing at least at 7 kPa(50 mmHg) and 27 kPa (200 mmHg)) and 6.4.4;

• internal nominal diameter and tolerance of the tubecontaining mercury; and

• detailed instructions for the safe handling ofmercury (see Annex C).

OIML R 16-1: 2002 (E)

10

A.1 Method of test for the maximumpermissible errors of the cuff pressureindication

A.1.1 Apparatus

• rigid metal vessel with a capacity of 500 ml ± 5 %;• calibrated reference manometer with an uncertainty

less than 0.1 kPa (0.8 mmHg);• pressure generator, e.g. ball pump (hand pump) with

a deflation valve;• T-piece connectors and hoses.

A.1.2 Procedure

Replace the cuff with the vessel. Connect the calibratedreference manometer by means of a T-piece connectorand hoses to the pneumatic system (see Figure 2). Afterdisabling the electromechanical pump (if fitted),connect the pressure generator into the pressuresystem by means of another T-piece connector. Carryout the test in pressure steps of not more than 7 kPa(50 mmHg) between 0 kPa (0 mmHg) and the max-imum pressure of the scale range.*



A.2 Method of test for the influence of temperature on cuff pressureindication

A.2.1 Apparatus

• apparatus as specified in A.1.1; plus• a climatic chamber.

A.2.2 Procedure


Annex A

Test procedures

(Mandatory)

* In case of doubt about the linearity, spot checks should becarried out or the width of the pressure steps should be reduced,i.e., from the normally recommended 7 kPa (50 mmHg) to 3 kPa(20 mmHg). This also applies to Table 1 in Annex B.

1 - Reference manometer 2 - Manometer of the device to be tested3 - Metal vessel4 - Pressure generator

Figure 2 Measurement system for determining the limits of errorof the cuff pressure indication

1111 2222 3333 4444

500 ml

21

43

1111 2222 3333 4444

OIML R 16-1: 2002 (E)

11

For each of the following combinations of temperatureand humidity, condition the device for at least 3 h in theclimatic chamber to allow the device to reach steadyconditions:

• 10 °C ambient temperature, 85 % relative humidity(non-condensing);

• 20 °C ambient temperature, 85 % relative humidity(non-condensing);

• 40 °C ambient temperature, 85 % relative humidity(non-condensing).

Carry out the test of the cuff pressure indication asdescribed in A.1.2 for each of the combinations oftemperature and humidity mentioned above.


Express the results as the differences between theindicated pressure of the manometer of the device to be

tested and the corresponding readings of the referencemanometer (see B.4) at the relevant temperature value.

A.3 Method of test for the maximumpermissible error after storage

A.3.1 Apparatus

• apparatus as specified in A.1.1.

A.3.2 Procedure


1111 2222 3333 4444

500 ml

21

3

45

1111 2222 3333 4444

1 - Reference manometer 2 - Climatic chamber 3 - Manometer of the device to be tested 4 - Metal vessel 5 - Pressure generator

Figure 3 Measurement system for determining the influence of temperature

OIML R 16-1: 2002 (E)

12

Store the instrument under test for 24 h at a temperat-ure of – 20 °C and subsequently for 24 h at a temper-ature of 70 °C and a relative humidity of 85 % (non-condensing).

Note: This is one test and not two separate tests.

Carry out the test in pressure steps of not more than7 kPa (50 mmHg) between 0 kPa (0 mmHg) and themaximum pressure of the scale range.



A.4 Method of test for air leakage of the pneumatic system

A.4.1 Apparatus

• rigid metal cylinder of an appropriate size (see 6.1);• pressure generator, e.g. ball pump (hand pump) with

a deflation valve;• time measuring device.

A.4.2 Procedure

Wrap the cuff around the cylinder.

Note: Electro-mechanical pumps which are part of thedevice may be used for the test.

Carry out the test over the whole measuring range at atleast five equally spaced pressure steps (e.g. 7 kPa(50 mmHg), 13 kPa (100 mmHg), 20 kPa (150 mmHg),27 kPa (200 mmHg) and 34 kPa (250 mmHg)). Test theair leakage over a period of 5 min and determine themeasured value from this.


Express the air leakage as the rate of the pressure lossper minute.

A.5 Method of test for pressure reductionrate for deflation valves

A.5.1 Apparatus

• T-piece connector;• calibrated reference manometer with signal output

and an uncertainty less than 0.1 kPa (0.8 mmHg);• artificial limbs (see Notes under A.5.2);• recording unit.

A.5.2 Procedure

Measure the pressure reduction rate either on humanlimbs or artificial limbs.Note 1: The intention is to use artificial limbs, but as

these are still under consideration, measu-rements performed with human volunteers areacceptable.

Note 2: It is intended that the properties of theartificial limbs reflect some elastic propertiesof human limbs.

Because cuff deflation rate may be influenced by theway that a cuff is applied, the cuff should be appliedand removed for each of at least ten repeatedmeasurements, on at least two different limb sizes.These two limb sizes should be equal to the upper andlower limits of limb circumferences for which aparticular size of cuff is recommended to be used. A re-setting of the deflation valve is permitted during thetest.

Connect the calibrated reference manometer to the cuffby means of a T-piece connector. Connect the output ofthe calibrated reference manometer to the recordingunit.

Plot the pressure reduction in the form of a pressurecurve as a function of time.


Determine the rate of pressure reduction by graphicalevaluation (by drawing tangents) at the pressure valuesof 8.0 kPa (60 mmHg), 16.0 kPa (120 mmHg) and24.0 kPa (180 mmHg). The pressure reduction rate isthe mean value calculated separately for these threepressure values and for the various limb circumfe-rences.

OIML R 16-1: 2002 (E)

13

A.6 Method of test for the rapid exhaustvalve

A.6.1 Apparatus

• rigid metal vessel, with a capacity of 500 ml ± 5 %;• calibrated reference manometer, with an uncertainty

less than 0.1 kPa (0.8 mmHg);• T-piece connector;• time measuring device.

A.6.2 Procedure

Carry out the test with the vessel in place of the cuff.

Connect the calibrated reference manometer by meansof a T-piece to the pneumatic system. Inflate to themaximum pressure and open the rapid exhaust valve.


Measure the time between the pressure values specifiedin 6.2.3.

A.7 Method of test for the thickness of the scale marks and the scale spacing

A.7.1 Apparatus

• scaled magnifying lens or similar device.

A.7.2 Procedure

Determine the thickness of the scale marks and thescale spacing using the scaled magnifying lens.

A.8 Method of test for the internaldiameter of the mercury tube

A.8.1 Apparatus

• limit plug gauges or similar devices, with a toleranceless than 0.05 mm.

A.8.2 Procedure

Test the nominal internal diameter of the tube at eachend by using the limit plug gauge.

A.9 Method of test for security againstmercury losses

A.9.1 Apparatus

• collecting vessel of an adequate size;• calibrated reference manometer, with an uncertainty

less than 0.1 kPa (0.8 mmHg);• T-piece connector;• pressure generator, e.g. ball pump (hand pump) with

a deflation valve.

A.9.2 Procedure

Place the sphygmomanometer to be tested in thecollecting vessel. Connect the pressure generator and aT-piece connector attached to a calibrated referencemanometer directly to the hose leading to the mercuryreservoir. Use the pressure generator to raise thepressure in the manometer to 13.3 kPa (100 mmHg)greater than the maximum indicated scale reading onthe test manometer. Maintain this pressure for 5 s andthen release the pressure in the system.

Check that no mercury has spilled.

A.10 Method of test for the influence of themercury stopping device

A.10.1 Apparatus

• time measuring device, e.g. a stopwatch or anelectronic timing device;

• pressure generator, e.g. ball pump (hand pump) witha deflation valve.

A.10.2 Procedure

Connect the pressure generator directly to the hoseleading to the mercury reservoir, i.e. without connect-

OIML R 16-1: 2002 (E)

14

ing a cuff. When a gauge pressure of more than 27 kPa(200 mmHg) has been reached, occlude the tube andremove the pressure generator.

After removing the occlusion from the tube, measurethe time taken for the mercury column to fall from the27 kPa (200 mmHg) mark to the 5 kPa (40 mmHg)mark.

Check that the exhaust time does not exceed 1.5 s.

A.11 Method of test for the hysteresis errorof the aneroid manometer

A.11.1 Apparatus

• rigid metal vessel, with a capacity of 500 ml ± 5 %;• calibrated reference manometer, with an uncertainty

less than 0.1 kPa (0.8 mmHg);• pressure generator, e.g. ball pump (hand pump) with

a deflation valve;• T-piece connectors.

A.11.2 Procedure

Replace the cuff with the vessel. Connect the calibratedreference manometer by means of a T-piece connectorto the pneumatic system. After disabling the electro-mechanical pump (if fitted) connect the additionalpressure generator into the pneumatic system bymeans of another T-piece connector.

Test the device with increasing pressure steps of notmore than 7 kPa (50 mmHg) to the scale maximum, atwhich point hold the pressure for 5 min and thendecrease it by the same steps. Disconnect the calibratedreference manometer during the 5 min at maximumpressure.


Express the results as the difference between theindicated values on the manometer at the same testpressure steps when increasing the pressure and whendecreasing the pressure.

A.12 Method of test for the construction

A.12.1 Apparatus

• alternating pressure generator, which generates asinusoidal pressure variation between 3 kPa and30 kPa (20 mmHg and 220 mmHg) at a maximumrate of 60 cycles per minute.

A.12.2 Procedure

Carry out the procedure specified in A.1.

Connect the aneroid manometer directly to thealternating pressure generator and perform 10 000alternating pressure cycles.

One hour after the stress test carry out the procedure asspecified in A.1 at the same test pressure levels asbefore the stress test.


Express the results as the differences between theindicated values on the manometer at the same testpressure steps before and after the stress test.

OIML R 16-1: 2002 (E)

15

Explanatory notes on the test report format

i) General

This Test report format, which is informative with regard to the implementation of OIML Recommendation R 16-1in national regulations, presents a standardized format for the results of the various tests and examinations to whicha type of sphygmomanometer shall be submitted with a view to its approval as well as for the results of verificationtests. The tests are listed in Annex A of this International Recommendation.

It is recommended that all metrology services or laboratories evaluating types of sphygmomanometers according toOIML R 16-1 or to national or regional regulations based on OIML R 16-1 use this Test report format, directly or aftertranslation into a language other than English or French.

It is also recommended that this Test report format in English or in French (or in both languages) be transmitted bythe country performing these tests to the relevant authorities of another country, under bi- or multi-lateralcooperation agreements.

In the framework of the OIML Certificate System for Measuring Instruments, use of the Test report format ismandatory.

ii) Page numbering and the use of report page formats

In addition to the sequential numbering at the bottom of each page, a space has been left at the top of each page(starting on page 18) for numbering the pages of reports established following this model. In particular, each test isreported individually on a separate page following the relevant format.

For a given report, it is advisable to complete the sequential numbering of each page by indicating the total numberof pages in the report.

Where required, pressure values in the Tables can be replaced by values expressed in kPa.

Where required, these forms can be copied and used several times in cases where the test in question has to berepeated under varying conditions.

iii) Definitions and formula

For the purposes of this test report format, the following definitions and formula, taken from the InternationalVocabulary of Basic and General Terms in Metrology (VIM, 1993 edition) are used.

Conventional true value (of a quantity) [VIM 1.20]

value attributed to a particular quantity and accepted, sometimes by convention, as having an uncertainty appropriate for givenpurpose.

Annex B

Test Report Format

(Mandatory for application within the OIML Certificate System for Measuring Instruments)

OIML R 16-1: 2002 (E)

16

EXAMPLES

a) at a given location, the value assigned to the quantity realized by a reference standard may be taken as a conventional true value;

b) the CODATA (1986) recommended value for the Avogadro constant NA: 6,022 136 7 × 1023 mol–1.

NOTES

1 “Conventional true value” is sometimes called assigned value, best estimate of the value, conventional value or reference value.“Reference value”, in this sense, should not be confused with “reference value” in the sense used in the note to VIM 5.7.

2 Frequently, a number of results of measurements of a quantity is used to establish a conventional true value.

Experimental standard deviation [VIM 3.8]

for a series of n measurements of the same measurand, the quantity s characterizing the dispersion of the results and given by theformula:

xi being the result of the ith measurement and x– being the arithmetic mean of the n results considered.

NOTES

1 Considering the series of n values as a sample of a distribution, x– is an unbiased estimate of the mean µ, and s2 is an unbiasedestimate of the variance σ 2, of that distribution.

2 The expression s / n is an estimate of the standard deviation of the distribution of x– and is called the experimental standarddeviation of the mean.

3 “Experimental standard deviation of the mean“ is sometimes incorrectly called standard error of the mean.

Uncertainty of measurement [VIM 3.9]

parameter, associated with the result of a measurement, that characterizes the dispersion of the values that could reasonably beattributed to the measurand.

NOTES

1 The parameter may be, for example, a standard deviation (or a given multiple of it), or the half-width of an interval having a statedlevel of confidence.

2 Uncertainty of measurement comprises, in general, many components. Some of these components may be evaluated from thestatistical distribution of the results of series of measurements and can be characterized by experimental standard deviations. Theother components, which can also be characterized by standard deviations, are evaluated from assumed probability distributionsbased on experience or other information.

3 It is understood that the result of the measurement is the best estimate of the value of the measurand, and that all components ofuncertainty, including those arising from systematic effects, such as components associated with corrections and referencestandards, contribute to the dispersion.

This definition is that of the “Guide to the expression of uncertainty in measurement” in which its rationale is detailed (see, inparticular, 2.2.4 and annex D [10]).

s = (xi – x–)2

n – 1

Σn

i = 1

OIML R 16-1: 2002 (E)

17

Error (of measurement) [VIM 3.10)]

result of a measurement minus a true value of the measurand.

NOTES

1 Since a true value cannot be determined, in practice a conventional true value is used (see VIM 1.19 and VIM 1.20).

2 When it is necessary to distinguish “error“ from “relative error”, the former is sometimes called absolute error of measurement.This should not be confused with absolute value of error, which is the modulus of the error.

Deviation [VIM 3.11]

value minus its reference value.

Systematic error [VIM 3.14]

mean that would result from an infinite number of measurements of the same measurand carried out under repeatability conditionsminus a true value of the measurand.

NOTES

1 Systematic error is equal to error minus random error

2 Like true value, systematic error and its causes cannot be completely known.

3 For a measuring instrument, see “bias” (VIM 5.25).

Maximum permissible errors (of a measuring instrument) [VIM 5.21]

extreme values of an error permitted by specifications, regulations, etc. for a given measuring instrument.


18

TYPE APPROVAL TEST REPORT VERIFICATION TEST REPORT

(For verification purposes tick those fields which are appropriate for verificationaccording to your national regulations or which are listed in B.1.2

under the heading: Summary of test results for verification.)

Number of report: ....................................................

Object: ...................................................................................................................................................................................

Type: ......................................................................................................................................................................................

Serial number: ......................................................................................................................................................................

Manufacturer’s name and address: .....................................................................................................................................

................................................................................................................................................................................................

................................................................................................................................................................................................

Customer’s name and address: ............................................................................................................................................

................................................................................................................................................................................................

................................................................................................................................................................................................

Date of receipt: .....................................................................................................................................................................

Date/period of measurement: ..............................................................................................................................................

Date of report: .................................................................. Number of pages: ...................................................................

Issuing Institute’s name and address: .................................................................................................................................

................................................................................................................................................................................................

................................................................................................................................................................................................

Characteristic values (principle of measurement, measuring unit, measuring range, range of display): ...................................................................................................................................

................................................................................................................................................................................................

Additional devices (printer, interface etc.): ........................................................................................................................

................................................................................................................................................................................................

Reference manometer (serial number, uncertainty, calibration certificate): ...................................................................

................................................................................................................................................................................................

Stamp/signature:

Non-invasive mechanical sphygmomanometersOIML R 16-1 Edition 2002 (E)

TEST REPORT

19


B.1 Test review

B.1.1 Summary of test results for type approval



B.3 Effect of storage on cuff pressure indication



B.6 Pressure reduction rate for deflation valves

B.7 Rapid exhaust valve

B.8 Resistance to vibration and shock

B.9 Electrical safety



B.10.2 Analogue indication - Scale

B.10.3 Analogue indication - First scale mark

B.10.4 Analogue indication - Scale interval

B.10.5 Scale spacing and thickness of scale marks

B.11 Additional technical requirements for mercury manometers

B.11.1 Internal diameter of the tube containing mercury

B.11.2 Portable devices

B.11.3 Device to prevent mercury from being spilled (use/transport)

B.11.4 Performance of this device

B.11.5 Quality of the mercury

B.11.6 Graduation of the mercury tube

B.12 Additional requirements for aneroid manometer

B.12.1 Scale mark at zero

B.12.2 Zero

B.12.3.1 Pointer length

B.12.3.2 Pointer thickness

B.12.4 Hysteresis error

B.12.5 Construction and materials


20


B.1.2 Summary of test results for verification

Note 1: The sequence of the different tests is arbitrary; it follows the sequence of the different clauses in the text.The sequence of testing is at the discretion of the person conducting the tests.

Note 2: To be considered as approved or verified, an instrument must have successfully passed all the applicabletests.

B.2 Maximum permissible errors of the cuff pressure indication

For the limits of temperature and humidity see 5.1.1: the temperature should be between 15 °C and 25 °C, therelative humidity should be between 20 % and 85 %.

To find out the error of the cuff pressure indication proceed as follows (up and down runs) at three differenttemperatures: e.g. 15 °C and 20 % relative humidity, 20 °C and 60 % relative humidity and 25 °C and 85 % relativehumidity.

Table 1 Example: Temperature 20 °C and …. % relative humidity

maximum deviation: 5 mmHg maximum hysteresis: 6 mmHg

1 2 3 4 5 6 7 8 9 10 11

pressure1st reading 2nd reading mean deviation hysteresis

mmHg up down up down up down up down1st 2nd

reading reading

0 2 0 0 4 1 2 1 2 2 4

50 52 54 54 54 53 54 3 4 2 0

100 106 100 104 104 105 102 5 2 6 0

150

200

250





B.9 Electrical safety

B.11.4 Performance of the device to prevent mercury from being spilled (use/transport)




21


Column 1 = values measured by the reference manometer

Column 2, 3, 4 and 5 = results of the measurement of the instrument under test





Column 10 = abs (column 2 – column 3)

Column 11 = abs (column 4 – column 5)

Table 2 Temperature 20 °C and ..... % relative humidity

Maximum deviation: ............. Maximum hysteresis: .............

Note 1: The hysteresis error is the difference between the indications of the instrument when the same pressure isreached by increasing or decreasing the pressure.

Note 2: The time between up and down run should not be less than 5 minutes at the maximum pressure (seeA.11.2). A time difference from the first run to the second run of one hour is recommended.

Is the maximum deviation of all of the readings of the instrument under test and of the reference manometer lessthan or equal to ± 0.4 kPa (± 3 mmHg) for type approval test and first verification and less than or equal to ± 0.5 kPa(± 4 mmHg) for subsequent verification, respectively (see 5.1.1)?

yes passed

no failed

1 2 3 4 5 6 7 8 9 10 11

pressure1st reading 2nd reading mean deviation hysteresis

mmHg up down up down up down up down1st 2nd

reading reading

0

50

100

150

200

250

300 or max

22


B.3 Effect of storage on cuff pressure indication

Refer to 5.1.2. Determine the error after the storage for 24 h at a temperature of – 20 °C and for 24 h at a temperatureof 70 °C and a relative humidity of 85 % (refer to Note 1 below).

Note 1: The measurements are to be performed before and after applying the test conditions, respectively:

• First measurement at 20 °C and 60 % relative humidity before the test (refer to Table 2);• Storage of the instrument under test for 24 hours at – 20 °C and 85 % relative humidity, immediately

followed by storage of the instrument under test for 24 hours at 70 °C and 85 % relative humidity;• Second measurement at 20 °C and 60 % relative humidity after the test.

The percentages for the relative humidity are arbitrary. The first measurement gives the reference values.

Each measurement requires two readings. Calculate the deviation of the mean of the two readings afterstorage in Table 3 from the mean calculated in Table 2. The result should be within the error limitsmentioned below.

Note 2: These conditions apply for mechanical blood pressure measuring instruments only.

Table 3 Measurement at 20 °C and 60 % relative humidity after storage at – 20 °C and 70 °C


Is the maximum deviation of the cuff pressure indication (mean value), after storage at – 20 °C and 70 °C, less thanor equal to ± 0.4 kPa (± 3 mmHg) compared to the mean values at 20 °C and 60 % relative humidity before storage?

yes passed

no failed

pressure1st reading after storage 2nd reading after storage mean


0

50

100

150

200

250

300 or max

deviation between the mean after storage and Table 2

23



Refer to 5.1.3.

Note 1: For a type approval test report testing has to be carried out also at 10 °C and 40 °C (see A.2.2).

Note 2: Take the first mean of the readings of the measuring instrument before storage as reference value (Table 2)and calculate the deviation of the mean of the values measured after storage (mean values here in Table 4)from the mean values of Table 2. The result should be within the error limits mentioned below.

For each of the following combinations of temperature and humidity, condition the device for at least 3 h in theclimatic chamber to allow the device to reach steady conditions.





Is the maximum deviation of all of the readings of the instrument under test and the reference manometer less thanor equal to ± 0.4 kPa (± 3 mmHg)?

yes passed

no failed



0

50

100

150

200

250

300 or max




0

50

100

150

200

250

300 or max


24



Carry out the test over the whole measuring range at five equally spaced pressure steps at least (e.g. 7 kPa(50 mmHg), 13 kPa (100 mmHg), 20 kPa (150 mmHg), 27 kPa (200 mmHg) and 33 kPa (250 mmHg)). Test the airleakage rate over a period of 5 min (see A.4.2), and determine the measured value from this.

Table 6

Does the air leakage rate over a period of 5 minutes correspond to a pressure drop less than or equal to 0.5 kPa/min(4 mmHg/min)?

yes passed

no failed

B.6 Pressure reduction rate for deflation valves

Manually operated deflation valves shall be capable of adjustment to a deflation rate of 0.3 kPa/s to 0.4 kPa/s(2 mmHg/s to 3 mmHg/s).

Manually operated deflation valves shall be easily adjusted to these values.

Deflation valves shall be tested in accordance with 6.2.2 and A.5.

Is the deflation rate adjustable to a value between 0.3 kPa/s and 0.4 kPa/s (2 mmHg/s and 3 mmHg/s)?

yes passed

no failed


Testing shall be carried out in accordance with 6.2.3 and A.6.

Time for the pressure reduction from 35 kPa to 2 kPa (260 mmHg to 15 mmHg): tRe = .........s

Is tRe less than 10 s?

yes passed

no failed

pressure first reading reading after 5 min difference between the readings

50 mmHg

100 mmHg

150 mmHg

200 mmHg

250 mmHg

25


B.8 Resistance to vibration and shock

Refer to 6.6.1. The mechanical conditions can be found in OIML D 11 (for example clause A.2.2 of the 1994 edition).

Does the instrument comply with 5.1.1 of this Recommendation after the vibration and shock test?

yes passed

no failed

B.9 Electrical safety (This test is optional within the OIML Certificate System)

If the instrument is equipped with electrical devices, do these devices comply with regional and national safetyregulations?

yes passed

no failed

B.10 Pressure indicating devices

All the tests can be carried out by visual inspection.

For reference see: Scale readable: 6.3.2.1

First scale mark: 6.3.2.2

Scale interval: 6.3.2.3

Scale spacing and thickness of scale marks: 6.3.2.4


Does the nominal range extend from 0 kPa to at least 35 kPa (0 mmHg to at least 260 mmHg)?

yes passed

no failed

B.10.2 Analogue indication - Scale

Is the scale clearly readable?

yes passed

no failed

26


B.10.3 Analogue indication - First scale mark

Is there a scale mark at 0 kPa (0 mmHg)?

yes passed

no failed

B 10.4 Analogue indication - Scale interval

Is the scale interval 0.2 kPa or 2 mmHg for a scale graduated in kPa or mmHg, respectively?

yes passed

no failed

B.10.5 Analogue indication - Scale spacing and thickness of scale marks

Is the distance between adjacent scale marks not less than 1.0 mm and does the thickness of the scale marks notexceed 20 % of the smallest scale spacing?

yes passed

no failed

Are the scale marks of equal thickness?

yes passed

no failed

B.11 Additional technical requirements for mercury manometers

B.11.1 Internal diameter of the tube containing mercury

Is the nominal internal diameter of the mercury tube at least 3.5 mm ± 0.2 mm?

yes passed

no failed


27


B.11.2 Portable devices

Does the portable device have an adjusting or locking mechanism to secure it in a specified position of use?

yes passed

no failed


B.11.3 Device to prevent mercury from being spilled during use and transport

Does the tube have a device to prevent the mercury from being spilled during transport and use and is this deviceefficient?

yes passed

no failed


B.11.4 Influence of the device to prevent mercury from being spilled during use and transport

Does the delay in the setting of the mercury column due to this device exceed 1.5 s for the flow of the mercury from27 kPa to 5 kPa (from 200 mmHg to 40 mmHg ) when the pressure in the system drops rapidly from 27 kPa to 0 kPa(from 200 mmHg to 0 mmHg)?

yes failed

no passed



For type approval only:

Does the supplier confirm that the purity of the mercury is not less than 99.99 %?

yes passed

no failed

For reference see 6.4.4.1

28


For type approval and for verification:

Does a visual inspection show a clean meniscus and no bubbles of air?

yes passed

no failed

For reference see 6.4.4.2.

B.11.6 Graduation of the mercury tube

Are the graduations permanently marked on the tube containing mercury?

yes passed

no failed


Note: Numbered at each fifth scale mark, the numbering shall be alternately on the right-hand and left-hand sideof, and adjacent to, the tube.


B.12 Additional requirements for aneroid manometers

B.12.1 Scale mark at zero

If a tolerance zone is shown at zero, is it smaller than ± 0.4 kPa (± 3 mmHg)?

yes passed

no failed


Note: Graduations within the tolerance zone are optional.

B.12.2 Zero

Is the movement of the elastic sensing element including the pointer obstructed within 0.8 kPa (6 mmHg) belowzero?

yes failed

no passed


Note: Neither the dial nor the pointer shall be adjustable by the user.

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B.12.3 Pointer



B.12.3.1 Pointer length

Does the pointer cover between 1/3 and 2/3 of the length of the shortest scale mark of the scale?

yes passed

no failed

B.12.3.2 Pointer thickness

Is the pointer thicker than the scale mark at the place of indication and does the distance between the pointer andthe dial exceed 2 mm?

yes failed

no passed


Is the maximum hysteresis error throughout the pressure range less than or equal to 0.5 kPa (4 mmHg) accordingto Table 2?

yes passed

no failed

Note: The purpose of this test is to determine if the elastic sensing element has been exposed to a tension withinthe elastic range (i.e. the “Hooke’s” range) or not throughout the whole pressure range.

For reference see 6.5.4. The test should be carried out according to A.11.

30


B.12.5 Construction and materials

Is the difference in the pressure indication of the aneroid manometer after 10 000 alternating pressure cycles morethan 0.4 kPa (3 mmHg) at any point within the pressure range?

yes failed

no passed

For reference see 6.5.5. The test should be carried out according to A.12. The pressure test has to be performedaccording to B.2.

Note: The construction of the aneroid manometer and the material for the elastic sensing elements shall ensure anadequate stability of the measurement. The elastic sensing elements shall be aged with respect to pressureand temperature.


Tamper proofing of the manometer shall be achieved by requiring the use of a tool.

Is the manometer tamper proof?

yes passed

no failed


Tests should be done by an appropriate inspection.

31

OIML R 16-1: 2002 (E)

Annex C

Advice to be included in the instructions accompanying a sphygmomanometer using a mercury manometer

(Informative)

C.1 Guidelines and precautions

A mercury-type sphygmomanometer should be handled with care. In particular, care should be taken to avoiddropping the instrument or treating it in any way that could result in damage to the manometer. Regular checksshould be made to ensure that there are no leaks from the inflation system and to ensure that the manometer hasnot been damaged so as to cause a loss of mercury.

C.2 Health and safety when handling mercury

Exposure to mercury can have serious toxicological effects; absorption of mercury results in neuropsychiatricdisorders and, in extreme cases, of nephrosis. Therefore precautions should be taken when carrying out anymaintenance to a mercury-type sphygmomanometer.

When cleaning or repairing the instrument, it should be placed on a tray having a smooth, impervious surface whichslopes away from the operator at about 10° to the horizontal, with a water-filled trough at the rear. Suitable gloves(e.g. of latex) should be worn to avoid direct skin contact. Work should be carried out in a well-ventilated area, andingestion and inhalation of the vapor should be avoided.

For more extensive repairs, the instrument should be securely packed with adequate padding, sealed in a plastic bagor container, and returned to a specialist repairer. It is essential that a high standard of occupational hygiene ismaintained in premises where mercury-containing instruments are repaired. Chronic mercury absorption is knownto have occurred in individuals repairing sphygmomanometers.

C.3 Mercury spillage

When dealing with a mercury spillage, wear latex gloves. Avoid prolonged inhalation of mercury vapor. Do not usean open vacuum system to aid collection.

Collect all the small droplets of split mercury into one globule and immediately transfer all the mercury into acontainer, which should then be sealed.

After removal of as much of the mercury as practicable, treat the contaminated surfaces with a wash composed ofequal parts of calcium hydroxide and powdered sulfur mixed with water to form a thin paste. Apply this paste to allthe contaminated surfaces and allow to dry. After 24 h, remove the paste and wash the surfaces with clean water.Allow to dry and ventilate the area.

C.4 Cleaning the manometer tube

To obtain the best results from a mercury-type sphygmomanometer, the manometer tube should be cleaned atregular intervals (e.g. under the recommended maintenance schedule). This will ensure that the mercury can moveup and down the tube freely, and respond quickly to changes in pressure in the cuff.

During cleaning, care should be taken to avoid the contamination of clothing. Any material contaminated withmercury should be sealed in a plastic bag before disposal in a refuse receptacle.

Printed in France GRANDE IMPRIMERIE DE TROYES