PRODUCT MANUAL

HT10X

HEAT TRANSFER SERVICE UNIT

HT10X

ISSUE 6

OCTOBER 2008

NOTE: Compatibility of HT10X with HT14 & HT16

In February 2006 a component becoming obsolete forced Armfield Ltd to change the mains outlet connector (OUTPUT 1) at the rear of the HT10X console and the corresponding plug on the mains lead of the HT14 and HT16. No other accessories to the HT10X are affected by this change.

An adaptor ‘ADAPTOR1–HT10’ is available from Armfield Ltd that allows a current HT10X to be used with an original HT14 or HT16. If the mains plug on your HT14 or HT16 has exposed pins that do not mate with OUTLET 1 on HT10X then ‘ADAPTOR1–HT10’ is required.

Similarly ‘ADAPTOR2-HT10’ is available from Armfield Ltd that allows an original HT10X to be used with a current HT14 or HT16. If the mains plug on your HT14 or HT16 has pins protected by a shrouded cover that does not mate with OUTLET 1 on HT10X then ‘ADAPTOR2-HT10’ is required.

If you need an adaptor please contact Armfield Ltd at the address below specifying if ‘ADAPTOR1-HT10’ or ‘ADAPTOR2-HT10’ is required for correct functioning of the equipment:

Armfield Ltd Bridge House West Street Ringwood Hampshire England BH24 1DY

Telephone number: +44 (0)142578781

Fax number: +44 (0)1425470916

Email address: support@armfield.co.uk

ARMFIELD LTD

PRODUCT MANUAL

HT10X

PAGE NO.

SAFETY 1

INTRODUCTION 5

RECEIPT OF EQUIPMENT 7

DESCRIPTION 9

INSTALLATION REQUIREMENTS 14

ASSEMBLY 15

CONNECTION TO SERVICES 16

COMMISSIONING 17

GENERAL OPERATING NOTES 18

ROUTINE MAINTENANCE 22

GENERAL SAFETY RULES a

1

SAFETY IN THE USE OF EQUIPMENT SUPPLIED BY ARMFIELD Before proceeding to install, commission or operate the equipment described in this product manual we wish to alert you to potential hazards so that they may be avoided. Although designed for safe operation, any laboratory equipment may involve processes or procedures which are potentially hazardous. The major potential hazards associated with this particular equipment are listed below. l INJURY THROUGH MISUSE l INJURY FROM ELECTRIC SHOCK l INJURY FROM INCORRECT HANDLING l BURNS FROM COMPONENTS AT HIGH TEMPERATURES l DAMAGE TO CLOTHING Accidents can be avoided provided that equipment is regularly maintained and staff and students are made aware of potential hazards. A list of general safety rules is included in this manual, to assist staff and students in this regard. The list is not intended to be fully comprehensive but for guidance only. Please refer to the notes overleaf regarding the Control of Substances Hazardous to Health Regulations.

2

The COSHH Regulations The Control of Substances Hazardous to Health Regulations (1988)

The COSHH regulations impose a duty on employers to protect employees and others from substances used at work which may be hazardous to health. The regulations require you to make an assessment of all operations which are liable to expose any person to hazardous solids, liquids, dusts, vapours, gases or micro-organisms. You are also required to introduce suitable procedures for handling these substances and keep appropriate records. Since the equipment supplied by Armfield Limited may involve the use of substances which can be hazardous (for example, cleaning fluids used for maintenance or chemicals used for particular demonstrations) it is essential that the laboratory supervisor or some other person in authority is responsible for implementing the COSHH regulations. Part of the above regulations are to ensure that the relevant Health and Safety Data Sheets are available for all hazardous substances used in the laboratory. Any person using a hazardous substance must be informed of the following: Physical data about the substance Any hazard from fire or explosion Any hazard to health Appropriate First Aid treatment Any hazard from reaction with other substances How to clean/dispose of spillage Appropriate protective measures Appropriate storage and handling Although these regulations may not be applicable in your country, it is strongly recommended that a similar approach is adopted for the protection of the students operating the equipment. Local regulations must also be considered.

3

USE OF EARTH LEAKAGE CIRCUIT BREAKER AS AN ELECTRICAL SAFETY DEVICE

The equipment described in this Product manual operates from a mains voltage electrical supply. The equipment is designed and manufactured in accordance with appropriate regulations relating to the use of electricity. Similarly, it is assumed that regulations applying to the operation of electrical equipment are observed by the end user. However, to give increased operator protection, Armfield Ltd have incorporated a Residual Current Device or RCD (alternatively called an Earth Leakage Circuit Breaker - ELCB) as an integral part of this equipment. If through misuse or accident the equipment becomes electrically dangerous, an RCD will switch off the electrical supply and reduce the severity of any electric shock received by an operator to a level which, under normal circumstances, will not cause injury to that person. At least once each month, check that the RCD is operating correctly by pressing the TEST button. The circuit breaker MUST trip when the button is pressed. Failure to trip means that the operator is not protected and the equipment must be checked and repaired by a competent electrician before it is used.

4

HT12

HT13

HT14 HT16

T2T12 T1

T11

T10 T3

T9 T4

T8 T5

T7 T6

R L

V Fw

REMOTE

MANUAL

VOLTAGE CONTROL

T1 T2 T3 T4 T6 T7 T8 T9 T10 T11 T120V 0V

/O

PORTarmfield HT10X HEAT TRANSFER SERVICE UNIT

MAINS

R L Ua

INSTRUMENTATION

Ua

ZERO

TEMPERATURE ░C

V/A/W/m /Lux/M/sec/L/min2

TEMPERATURE OUTPUT 10mV/░C (6V MAX)

T5

Fw

HT10X

HT11

HT17

HT15

5

INTRODUCTION The Armfield range of heat transfer laboratory teaching equipment comprises seven small scale accessories which demonstrate the three basic modes of heat transfer (conduction, convection and radiation) which result from differences in temperature. The factors which affect the rate of heat transfer can be investigated and some of the practical problems associated with the transfer of heat can be clearly demonstrated. The seven heat transfer accessories may be individually connected to a common bench top service unit (HT10X) which provides the necessary electrical supplies and measurement facilities for investigation and comparison of the different heat transfer characteristics. The ability to change the type of demonstration quickly, without the use of tools, and the fast response of the system (where practicable) to changes in heat input, temperature etc. allows the relevant teaching exercises to be carried out in a relatively short period of time. A singular advantage of the modular approach to the HT10X series is that the service unit will allow students to carry out project work in heat transfer either by constructing their own thermal models or by making additions to one of the original accessories. The following heat transfer accessories are available:

HT11 Linear heat conduction HT12 Radial heat conduction HT13 Laws of radiant heat transfer and radiant heat exchange HT14 Combined convection and radiation HT15 Extended surface heat transfer HT16 Radiation errors in temperature measurement HT17 Unsteady state heat transfer

This product manual describes the function of the HT10X 'Heat Transfer Service Unit'. Each of the individual heat transfer accessories (HT11 to HT17) is supplied with a combined product and teaching manual. The product manual describes the operation of the particular accessory when used in conjunction with the HT10X service unit in relation to those functions normally associated with the laboratory technician. The teaching manual describes the individual accessory in relation to those functions normally associated with the student or operator, namely how to perform the Laboratory Teaching Exercises appropriate to the accessory. Each exercise includes detailed instructions on how to record the appropriate readings and which calculations to perform to analyse the performance. Appropriate Operational Procedures are included in the teaching manual to provide the operator with pertinent information about how to operate the equipment. The HT10X 'Heat Transfer Service Unit' is essential equipment which provides a regulated, variable DC supply to the heating element on the appropriate heat transfer accessory. Instrumentation on the service unit comprises a digital indicator with selector switch to display the temperatures at relevant positions on the heat transfer accessory and a second

6

digital indicator with selector switch to indicate other relevant variables. All measurements are available as voltage signals for direct connection to a PC via an optional interface device (a PC interface and WindowsTM based software is supplied for each of the heat transfer accessories with the Optional Educational Software/Data Logging Accessory.) The service unit is housed in a robust steel enclosure and designed for bench mounting. Note that accessories HT11C, HT12C, HT14C and HT16C are designed to be used in conjunction with the HT10XC Heat Transfer Service Unit and cannot be used with HT10X because of additional functions included only on the HT10XC.

7

RECEIPT OF EQUIPMENT 1. SALES IN THE UNITED KINGDOM

The apparatus should be carefully unpacked and the components checked against the Advice Note. A copy of the Advice Note is supplied with this product manual for reference. Any omissions or breakages should be notified to Armfield Ltd within three days of receipt.

2. SALES OVERSEAS

The apparatus should be carefully unpacked and the components checked against the Advice Note. A copy of the Advice Note is supplied with this product manual for reference. Any omissions or breakages should be notified immediately to the Insurance Agent stated on the Insurance Certificate if the goods were insured by Armfield Ltd. Your own insurers should be notified immediately if insurance was arranged by yourselves.

8

A

T2T12 T1

T11

T10 T3

T9 T4

T8 T5T7 T6

R L

V Fw

REMOTE

MANUAL

VOLTAGE CONTROL

T1 T2 T3 T4 T6 T7 T8 T9 T10 T11 T120V 0V

/O

PORTarmfield HT10X HEAT TRANSFER SERVICE UNIT

MAINS

R L Ua

INSTRUMENTATION

Ua

ZERO

TEMPERATURE ░C

V/A/W/m /Lux/M/sec/L/min2

B C D E

F

G

H

KLM

TEMPERATURE OUTPUT 10mV/░C (6V MAX)

T5

P

O

N

H J

Fw

OUTPUT 1 A.C. ~ 4A MAX

OUTPUT 324V D.C. 10A MAX

OUTPUT 2 A.C. ~ 1A MAX

O/P 3

R.C.C.B

MAINS INPUT A.C.~

Q R

X

W

V TU S

O/P 1 O/P 2

Rear View of HT10X

Front View of HT10X

9

DESCRIPTION Refer to the diagrams on page 8. The HT10X 'Heat Transfer Service Unit' is essential equipment designed to support the operation of the seven Armfield small scale heat transfer accessories:-

HT11 Linear heat conduction HT12 Radial heat conduction HT13 Laws of radiant heat transfer and radiant heat exchange HT14 Combined convection and radiation HT15 Extended surface heat transfer HT16 Radiation errors in temperature measurement HT17 Unsteady state heat transfer

which may be purchased singly. The appropriate heat transfer accessory is located on the bench top alongside the service unit and connected to the service unit, as appropriate, using the leads incorporated on the accessory. The service unit provides a stabilised, variable low voltage DC supply to the heat transfer accessory under evaluation. It incorporates the necessary instrumentation to measure the variables associated with heat transfer, namely:

- temperatures - heater power (voltage & current) - heat radiated - light radiated - air velocity - cooling water flowrate

The service unit requires a single phase electrical supply. A cold water supply is also required for several of the accessories (cold water supply and drain connected directly to the appropriate accessory). The service unit is designed for safe operation as follows: REAR OF SERVICE UNIT The following facilities are provided on the rear panel of the service unit:- The Residual Current Circuit Breaker (V) is a device for the protection of personnel in the event of an electrical fault or short to earth. All electrical circuits inside the service unit and all accessories connected to it are protected by this device. The operation, purpose and testing of the Residual Current Device are explained in more detail on page 3. Normal operation of the equipment is achieved with the switch in the UP position.

10

The service unit is provided with a 4 metre length of mains cable which is fitted with a plug to suit the mains power input socket (W). The cable allows connection of the unit to an appropriate electrical supply (refer to the section Connection to Services). The mains power output socket OUTPUT 1 (Q) is a mains power source used for driving external ancillary equipment up to 4 Amps maximum but specifically the accessories HT14 and HT16 which incorporate a mains powered centrifugal fan. A circuit breaker (U) limits the current available from this socket and protects the service unit and wiring in the event of a short circuit. The mains supply from OUTPUT 1 is at the same voltage and frequency as the electrical supply to the service unit. The mains power output socket OUTPUT 2 (X) is a mains power source used for driving external ancillary equipment up to 1 Amp maximum but specifically to power the Armfield IFD5 Interface Device, supplied with the Optional Educational Software/Data Logging Accessory. A circuit breaker (T) limits the current available from this socket and protects the service unit and wiring in the event of a short circuit. The mains supply from OUTPUT 2 is at the same voltage and frequency as the electrical supply to the service unit. The low voltage DC export socket OUTPUT 3 (S) is used to provide variable DC voltage from 0 to 24 V to the heater on the appropriate heat transfer accessory and provides immunity from fluctuations in the mains electrical supply. This supply is also used to operate the circulating pump when using the HT17 accessory. The electrical lead and matching plug are integral with the appropriate accessory. A thermal circuit breaker marked O/P 3 (R) limits the current available from this socket and protects the service unit and wiring in the event of a short circuit. Normal operation of the equipment is achieved with the switch on each of the above breakers in the UP position (button depressed in the case of O/P 3). If any of the above breakers are activated, this indicates a fault in the particular circuit and if the breaker will not reset, further investigation will be required by a competent electrician. FRONT OF SERVICE UNIT The following facilities are provided on the front panel of the service unit:- A mains switch (A), located on the front of the service unit allows the service unit to be turned on and off as required and isolates all of the individual electrical circuits inside the enclosure when switched off. The variable DC voltage supplied to the heat transfer accessory, via socket OUTPUT 3 at the rear of the service unit, is adjusted using the multi-turn potentiometer (C) marked VOLTAGE CONTROL. The range of the output voltage is continuously adjustable from 0 Volts to 24 Volts DC using the multi-turn potentiometer. The selector switch (B), adjacent

11

to the potentiometer, should be set to the MANUAL position to allow adjustment using the potentiometer. The selector switch is only set to the REMOTE position if the voltage is to be controlled from an external signal via the 50 way I/O Port connector (F). The actual voltage supplied can be monitored using the top panel meter (D) when the measurement selector switch (E) is set to position V. The readout is calibrated directly in Volts with a range of 0 to 24 VDC and a resolution of 0.1 Volts. Similarly the current can be monitored when the selector switch (E) is set to position I. The readout is calibrated directly in Amps with a range of 0 - 9 A and a resolution of 0.01 A. Other relevant parameters on the heat transfer accessories can be measured as follows: Thermal radiation R A radiometer is incorporated on the HT13 to measure the thermal radiation. This instrument is connected to the socket marked R (O) on the front of the service unit. The thermal radiation is read on the top panel meter (D) when the measurement selector switch (E) is set to position R. The thermal radiation is indicated directly in units of Watts/metre2 over the range 0 - 333 W/m2 with a resolution of 1 W/m2. A zero potentiometer (P) to the left of the radiometer socket allows any offset in the reading from the radiometer to be corrected. Light illumination L A light sensor is incorporated on the HT13 to measure the light illumination. This instrument is connected to the socket marked L (N) on the front of the service unit. The light illumination is read on the top panel meter (D) when the measurement selector switch (E) is set to position L. The light illumination is indicated directly in units of Lux over the range 0 - 234 Lux with a resolution of 1 Lux.

12

Air Velocity Ua A vane type anemometer is incorporated on the HT14 and HT16 to measure the velocity of the air passing through the duct. This instrument is connected to the socket marked Ua (M) on the front of the service unit. The air velocity is read on the top panel meter (D) when the measurement selector switch (E) is set to position Ua. The air velocity is indicated directly in units of metres/second over the range 0 - 10 m/s with a resolution of 0.1 m/s. Cooling Water Flowrate Fw: When the optional flow sensor is used in conjunction with the heat transfer accessories HT11 or HT12 the sensor is connected to the socket marked Fw (L) on the front of the service unit. The flow of cooling water is read on the top panel meter (D) when the selector switch (E) is set to position Fw. The flowrate is indicated directly in units of litres/min over the range 0 - 1.50 l/min with a resolution of 0.01 l/min. Where cooling water is required for the heat transfer accessory under evaluation, the water and drain connections are made directly to the appropriate accessory. Temperatures T1 - T12: Temperatures on the various heat transfer accessories are measured using up to 12 type K thermocouples installed in appropriate tappings on the accessory (thermocouples are supplied with the accessory). Each thermocouple lead is numbered to allow connection to the appropriate thermocouple socket (K) at the bottom of the front panel on the service unit. The required temperature reading is selected via a switch (G) and displayed on the adjacent panel meter (J). Temperature readings are displayed directly on the meter in units of °C. Thermocouples T1 - T9 are connected using miniature plugs/sockets. Readings are in the range 0 to 200°C with a resolution of 0.1°C. Thermocouples T10 - T12 are connected using standard plugs/sockets. Readings are in the range 0 to 600°C with a resolution of 1°C. (The sockets are polarised by size to prevent high temperature thermocouples from being connected to low temperature channels.) A row of banana sockets (I) on the front of the service unit allow any of the temperature signals to be connected to a suitable chart recorder. The output voltage from these sockets is 10 mV/°C (1 Volt corresponds to 100°C). The chart recorder input is connected to one of the black 0 Volt common sockets (H) and the appropriate red socket (T1 - T12) as required.

13

A 50 way IDC socket (F) on the right hand side of the front panel (The Data I/O Port) allows all of the temperatures and other measurements to be connected simultaneously to a PC via an optional Armfield IFD5 interface device which is supplied with the Optional Educational Software/Data Logging Accessory. Educational and Data Logging Software is available for all of the HT10X range of Heat Transfer equipment. Used in conjunction with the Armfield IFD5 interface device, which connects the HT10X Service Unit to the parallel printer port of a PC, this provides a comprehensive educational software environment within which the heat transfer investigations can be performed. Refer to Armfield for further information on the computer software available.

14

INSTALLATION REQUIREMENTS ELECTROMAGNETIC COMPATIBILITY This apparatus is classified as Education and Training Equipment under the Electromagnetic Compatibility (Amendment) Regulations 1994. Use of the apparatus outside the classroom, laboratory or similar such place invalidates conformity with the protection requirements of the Electromagnetic Compatibility Directive (89/336/EEC) and could lead to prosecution. FACILITIES REQUIRED Installation may be completed using a basic tool kit. The 'Heat Transfer Service Unit' is designed for installation on a firm, level work surface, such as a laboratory bench. Space should be allowed alongside the service unit for the installation of appropriate heat transfer accessories. As some of the heat transfer accessories require a permanent cold water supply during operation the location should be adjacent to a sink unit or cold water supply with appropriate drain. Where cooling water is required for the heat transfer accessory under evaluation, the water and drain connections are made directly to the appropriate accessory. Several of the teaching exercises, when using the HT13 accessory, involve the measurement of visible light. A darkened room will be required to allow accurate measurements to be taken. MAINS ELECTRICAL SUPPLY The 'Heat Transfer Service Unit' requires connection to a single phase fused electrical supply. Four metres of cable is supplied with the equipment, terminated with a plug to suit the mains input connector (W) on the rear panel. Two versions of the service unit are available:

HT10X-A 220/240V/1ph/50Hz @ 10 Amps HT10X-B 120V/1ph/60Hz @ 20 Amps

No other services are required. Overall dimensions of the HT10X are:

Width 320 mm Depth 390 mm Height 240 mm

The service unit requires one of the available heat transfer accessories (HT11, HT12, HT13 HT14, HT15, HT16 or HT17) to be connected to it to be fully operational.

15

ASSEMBLY The 'Heat Transfer Service Unit' is delivered fully assembled and ready for use with one of the heat transfer accessories HT11 - HT17.

16

CONNECTION TO SERVICES Refer to the diagrams on page 8. ELECTRICAL SUPPLY FOR VERSION HT10X-A Before connecting the electrical supply ensure that the RCD/RCCB (V) and two miniature circuit breakers O/P 1 (U) and O/P 2 (T) are in the OFF (down) position. The equipment requires connection to a single phase, fused electrical supply. The standard electrical supply for this equipment is 220/240V, 50Hz. Check that the voltage and frequency of the electrical supply agree with the label attached to the supply cable on the equipment. Connection should be made as follows:-

GREEN/YELLOW - EARTH BROWN - LIVE (HOT) BLUE - NEUTRAL Fuse rating - 6 AMP

ELECTRICAL SUPPLY FOR VERSION HT10X-B Before connecting the electrical supply ensure that the RCD/RCCB (V) and two miniature circuit breakers O/P 1 (U) and O/P 2 (T) are in the OFF (down) position. The equipment requires connection to a single phase, fused electrical supply. The standard electrical supply for this equipment is 120V, 60Hz. Check that the voltage and frequency of the electrical supply agree with the label attached to the supply cable on the equipment. Connection should be made as follows:-

GREEN/YELLOW - EARTH BROWN - LIVE (HOT) BLUE - NEUTRAL Fuse rating - 10 AMP

17

COMMISSIONING Refer to the diagrams on page 8. The following procedure is used for checking that the service unit is operating correctly. A full commissioning procedure is given in the individual product manuals for each of the heat transfer accessories. The following procedure relates to the HT10X 'Heat Transfer Service Unit' only:- Ensure that the service unit has been set up in accordance with the previous sections of this manual. 1. Ensure that the mains on/off switch (A) on the front panel is in the OFF position. 2. Ensure that the mains electrical supply is connected and switched on.

Check the operation of the RCD/RCCB (V) by pressing the TEST button. The RCD must trip when the button is pressed. If the RCD does not trip or it trips before pressing the test button then it must be checked by a competent electrician before the equipment is used.

3. Ensure that the RCD/RCCB (V) and the two miniature circuit breakers O/P 1 (U)

and O/P 2 (T) on the rear panel are in the ON (up) position. Ensure that the thermal circuit breaker O/P 3 (R) on the rear panel is latched (pressed in).

4. Set the mains on/off switch (A) on the front panel to the ON position. Observe that

the two digital panel meters are both illuminated. As sensors are not fitted at this stage the temperature display will indicate ambient temperature.

5. Set the voltage control switch to MANUAL. Set the measurement selector switch

(E) to position V. Adjust the multi-turn potentiometer to zero (release the clamp and turn the adjusting knob fully anticlockwise) then check that the reading indicated on the panel meter D) is approximately 0 Volts. Gradually turn the potentiometer clockwise and check that the reading Voltage indicated on the panel meter increases. When the potentiometer is fully clockwise the reading should be 24 Volts.

6. Switch off the service unit using the mains switch (A) on the front panel. Further checks on the function of the service unit cannot be carried out unless an appropriate heat transfer accessory is connected. The basic operation of the service unit has been confirmed. Refer to the section GENERAL OPERATING NOTES in this manual or the teaching manual supplied with each optional heat transfer accessory for further information.

18

GENERAL OPERATING NOTES SETTING THE HEATER VOLTAGE (All accessories except HT17) When operating the equipment manually using the front panel controls ensure that the selector switch (B) is set to the MANUAL position. This allows the voltage supplied to the heater to be adjusted using the multi-turn potentiometer (C) marked VOLTAGE CONTROL. The selector switch is only set to the REMOTE position if the voltage is to be controlled from an external signal via the 50 way I/O Port connector (F). The range of the output voltage is continuously adjustable from 0 Volts to 24 Volts DC using the multi-turn potentiometer. (Ensure that the clamp on the side of the knob is released before turning the knob.) Note: The 24 volt DC supply is used to operate the circulating pump on the accessory

HT17. The pump is connected to the DC outlet socket (OUTPUT 3) on the rear panel of the service unit. The speed of the pump can be adjusted by varying the setting of the multi-turn potentiometer in the same way as changing the voltage to a heater.

MEASURING THE POWER TO THE HEATER (All accessories except HT17) While adjusting the heater voltage the actual voltage supplied to the heater can be monitored by setting the selector switch (E) to position V. The reading is displayed directly in Volts on the top panel meter (D). The current drawn by the heater in the accessory can be monitored by setting the top measurement selector switch (E) to position I. The reading is displayed directly in Amps on the top panel meter (D). As the electrical supply to the heater is Direct Current the power supplied to the heater is simply obtained from the product of the Voltage and Current, ie. Heater Power Q = Voltage V x Current I eg. If V = 15.0 Volts and I = 2.00 Amps then Q = 2 x 15 = 30.0 Watts Note: Some of the accessories incorporate a thermostat to limit the maximum operating

temperature. If the heater voltage is set too high, resulting in excessive temperature, the current to the heater will be disconnected until the thermostat resets when the temperature falls. If the display shows no current when voltage is applied to the heating element check that the relevant temperature on the accessory is not excessive. If the temperature is excessive set the Voltage Control to zero and allow the thermostat to reset (Refer to the Operational Procedures in the teaching manual supplied with the accessory for further information).

19

If the temperature of the accessory is not excessive but the display shows no current

when voltage is applied to the heating element check the following: Check that the thermal breaker O/P3 (R) at the rear of the service unit is latched

(pressed in). Check that the heater lead on the accessory is connected to the socket marked O/P3

(S) at the rear of the service unit. MEASURING TEMPERATURES (T1 - T12 as appropriate on all accessories) To monitor any of the thermocouples installed on one of the heat transfer accessories simply set the temperature selector switch (G) to the required position and read the corresponding value on the lower panel meter (J). Temperatures T1 to T9 are indicated in the range 4.0 - 200.0°C with a resolution of one decimal place. Temperatures T10 to T12 are indicated in the range 4 - 600°C with a resolution of no decimal places. MEASURING THERMAL RADIATION (Radiometer on HT13) When the radiometer is connected to the socket (O) marked R then the thermal radiation can be read on the top panel meter (D) with the selector switch (E) set to position R. The thermal radiation is indicated directly in units of Watts/metre2 (maximum 333 W/m2). A zero potentiometer (P) to the left of the radiometer socket allows any offset in the reading from the radiometer to be corrected. MEASURING LIGHT ILLUMINATION (Lightmeter on HT13) When the lightmeter is connected to the socket (N) marked L then the illumination can be read on the top panel meter (D) with the selector switch (E) set to position L. The light illumination is indicated directly in units of Lux (maximum 234 Lux).

20

MEASURING AIR VELOCITY (Anemometer on HT14 and HT16) When the anemometer is connected to the socket (M) marked Ua then the air velocity can be read on the top panel meter (D) with the selector switch (E) set to position Ua. The air velocity is indicated directly in units of metres/second (maximum 10.0 m/s). MEASURING COOLING WATER FLOW RATE (Optional flow sensor on HT11 and HT12) If the optional flow sensor SFT2 is connected to the socket (L) marked Fw then the flowrate can be read on the top panel meter (D) with the selector switch (E) set to position Fw. The cooling water flowrate is indicated directly in units of Litres/min (Maximum 1.50 l/min). USING A CHART RECORDER Each of the temperature measurements is available as a voltage signal suitable for connection to a suitable chart recorder. The signals are accessible via a row of banana sockets (I) on the front panel of the service unit. Each thermocouple is conditioned to produce an output signal of 10 mV per °C. For example the Voltage output is 0.5 VDC at 50°C. The signal is obtained by connecting the chart recorder between the appropriate red channel socket (I), eg. T1 and one of the black 0V common connections (H). Note: Channels T1 to T9 are restricted to operation over the range 0 - 200°C (0 - 2 Volts

output). Channels T10 - T12 operate over the range 0 - 600°C (0 - 6 Volts output) USING THE OPTIONAL EDUCATIONAL SOFTWARE/DATA LOGGING ACCESSORY An I/O Data Port connector (F) on the right hand side of the front panel allows the voltage signals from each of the measurements to be connected to the parallel port of a suitable PC using an Armfield IFD5 interface device. This interface device together with the appropriate WindowsTM based software is available as an optional accessory to accompany the HT10X and heat transfer accessories HT11 to HT17. The operation of the interface is described in the instruction manual supplied with the IFD5. The operation of the WindowsTM based software is described in the help text included as part of the software.

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CONNECTIONS TO THE I/O DATA PORT To allow access to the measurement signals in applications other than when using an Armfield IFD5, the connections to the 50 way connector (F) are listed below for information:- PIN NO CHANNEL NO SIGNAL FUNCTION Analog Outputs (0-5 V dc exported from socket): 1 Ch 0 signal Temperatures T1 to T12 via analog switch Temperatures T1 - T9 (0 - 200°C) Temperatures T10 - T12 (0 - 600°C) 2 Ch 0 return 3 Ch 1 signal Voltage V (0 - 24 Volts DC) 4 Ch 1 return 5 Ch 2 signal Current to heater I (0 - 10 Amps) 6 Ch 2 return 7 Ch 3 signal Thermal Radiation R (0 - 333 W/m2) HT13 8 Ch 3 return 9 Ch 4 signal Light illumination L (0 - 234 Lux) HT13 10 Ch 4 return 11 Ch 5 signal Velocity of air Ua (0 - 10 m/s) HT14 and HT16 12 Ch 5 return 13 Ch 6 signal Flowrate of water Fw (0 - 1.5 l/min) HT11 and HT12 14 Ch 6 return 15-21 Not used Analog Inputs (0-5 V dc input to socket): 22 DAC0 signal Voltage output V (Remote operation of 0 - 24 Volts) 23 DAC0 ground 24-25 Not used Digital Outputs ( 0/5 V dc): 26-37) Not used Digital Inputs (0/5 V dc): 38 Ch 0 Analog switch 39 Ch 1 Analog switch 40 Ch 2 Analog switch 41 Ch 3 Analog switch 42 Digital ground 43 Ch 4 Inhibit analog switch 44-46 Not used 47 Digital ground 48-50 Not used

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ROUTINE MAINTENANCE To preserve the life and efficient operation of the equipment it is important that the equipment is properly maintained. Regular servicing/maintenance of the equipment is the responsibility of the end user and must be performed by qualified personnel who understand the operation of the equipment. In addition to regular maintenance the following notes should be observed:- 1. The 'Heat Transfer Service Unit' should be disconnected from the electrical supply

when not in use. 2. The heat transfer accessory under evaluation should be disconnected from the

service unit and drained (if appropriate) after use. 3. The thermocouple conditioning circuits (which provide readings from the

thermocouples fitted to each of the heat transfer accessories) are located on a PCB inside the electrical console. These circuits are calibrated before despatch and should not require recalibration. However, should recalibration become necessary the appropriate zero and span potentiometers can be located using the diagram on page 27.

This exercise should only be carried out by a competent electrician since live electrical circuits inside the electrical console will be exposed when the lid is removed.

A Type K thermocouple simulator should be connected to each socket in turn on the front of the service unit and the corresponding zero and span potentiometers adjusted to calibrate the circuit. Calibration at 0°C and 100°C is recommended on channels 1 to 9, calibration at 0°C and 500°C is recommended on channels 10 to 12. If a thermocouple simulator is not available then a type K thermocouple from one of the optional heat exchangers can be used with crushed ice and boiling water as the reference points.

4. Test the RCD/RCCB by pressing the TEST button at least once a month. If the RCD

does not trip when the TEST button in pressed then the equipment must not be used and should be checked by a competent electrician.

NOTE: Maintenance of the HT10X 'Heat Transfer Service Unit' does not require

access to the electrical circuits or components located inside the metal enclosure. However, in the event of an electrical problem or recalibration of the thermocouple circuits being necessary, it may be necessary for a competent electrician to gain access to the inside of the enclosure as follows:

Ensure that the service unit is disconnected from the electrical supply (not just switched off). Disconnect any accessory connected to the service unit.

23

Unscrew the four socket headed screws on the sides of the enclosure. Carefully lift the top metal panel from the enclosure taking care to disconnect the earth connection between the top and bottom sections of the enclosure. The electrical circuits inside the enclosure are accessible for working on. A circuit diagram showing the mains and DC electrical circuits inside the enclosure is included on page 25 to assist in fault finding. Should it be necessary to remove the I/O PCB from inside the enclosure then the I/O PCB Connections diagram on page 27 shows the location and function of the electrical connectors on the PCB to aid reassembly Reassembly of the service unit is the inverse of the above instructions. Ensure that the earth connection between the top and bottom panels is remade before replacing the top metal panel. Details of the connections between the service unit and any of the accessories is given in the appropriate product manual supplied with each accessory.

Note: The 24 Volt DC power supply inside the enclosure (mounted on the base)

incorporates a 10 Amp fuse to protect the DC output from the supply. If no output is available from the socket OUTPUTS (S) when thermal breaker O/P3 is depressed then this fuse should be checked for continuity. The fuse is located in an in-line holder adjacent to the smoothing capacitors on the power supply.

The instrumentation switch mode DC power supply inside the enclosure (mounted on the rear panel) incorporates a 2 Amp fuse to protect the mains input to the power supply. If the panel meters on the front of the console do not illuminate when the RCD and mains switch are on then this fuse should be checked for continuity. The fuse is located in a holder at the bottom of the PCB.

24

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25

26

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27

Location of Temperature Calibration Potentiometers

on PCB

PCB Connectors

CO

NN

16

CONN 1

CONN 8 CONN 9 CONN 12

CONN 5

CO

NN

13

CONN 2 CONN 7

CONN 11

PSU

CONN 10

CONN 6

TEMPERATURE OUTPUT 10mV/°C (6V MAX)

T6 T7 T8 T9 T10 T11 T120V T1 T2 T3 T4 T5 0V

R L

V Fw

Ua

T2T12 T1

T11

T10 T3

T9 T4

T8 T5T7 T6

VOLTAGE CONTROL

R UaLFw

V/A/W/m/Lux/M/sec/L/min

TEMPERATURE °C

PSR

CONTROL

PCB

VR

1E

VR

1C

VR

1A

VR

2R

VR

1B

VR

1D

VR

3P

VR

3R

VR

3N

VR

2N

ZERO

SPAN

T1 T6T4T2T5 T3

T5T1 T3

T6T2 T4

VR

1H

VR

1K

T10T8

VR

1M

T12

VR

1L

VR

1J

VR

1G

T7T9T11

VR

2T

VR

2V

VR

3T

VR

3V

VR

2S

T11T7 T9

T12T8 T10

I

+T11 - +T9 - + T7- + T5 - + T3 - + T1 - + T2 - +T4- + T6 - +T8 - + T10 -+ T12 -

VR

3S

VR

2P

VR

1F

Location of Temperature Calibration Potentiometers

on PCB

PCB Connectors

a

GENERAL SAFETY RULES 1 Follow Relevant Instructions a Before attempting to install, commission or operate equipment, all

relevant suppliers’/manufacturers’ instructions and local regulations should be understood and implemented.

b It is irresponsible and dangerous to misuse equipment or ignore instructions, regulations or warnings.

c Do not exceed specified maximum operating conditions (eg. temperature, pressure, speed etc).

2 Installation a Use lifting tackle where possible to install heavy equipment. Where

manual lifting is necessary beware of strained backs and crushed toes. Get help from an assistant if necessary. Wear safety shoes where appropriate.

b Extreme care should be exercised to avoid damage to the equipment during handling and unpacking. When using slings to lift equipment, ensure that the slings are attached to structural framework and do not foul adjacent pipework, glassware etc. When using fork lift trucks, position the forks beneath structural framework ensuring that the forks do not foul adjacent pipework, glassware etc. Damage may go unseen during commissioning creating a potential hazard to subsequent operators.

c Where special foundations are required follow the instructions provided and do not improvise. Locate heavy equipment at low level.

d Equipment involving inflammable or corrosive liquids should be sited in a containment area or bund with a capacity 50% greater than the maximum equipment contents.

e Ensure that all services are compatible with the equipment and that independent isolators are always provided and labelled. Use reliable connections in all instances, do not improvise.

f Ensure that all equipment is reliably earthed and connected to an electrical supply at the correct voltage. The electrical supply must incorporate a Residual Current Device (RCD) (alternatively called an Earth Leakage Circuit Breaker - ELCB) to protect the operator from severe electric shock in the event of misuse or accident.

g Potential hazards should always be the first consideration when deciding on a suitable location for equipment. Leave sufficient space between equipment and between walls and equipment.

b

3 Commissioning a Ensure that equipment is commissioned and checked by a competent

member of staff before permitting students to operate it. 4 Operation a Ensure that students are fully aware of the potential hazards when

operating equipment. b Students should be supervised by a competent member of staff at all

times when in the laboratory. No one should operate equipment alone. Do not leave equipment running unattended.

c Do not allow students to derive their own experimental procedures unless they are competent to do so.

d Serious injury can result from touching apparently stationary equipment when using a stroboscope to `freeze´ rotary motion.

5 Maintenance a Badly maintained equipment is a potential hazard. Ensure that a

competent member of staff is responsible for organising maintenance and repairs on a planned basis.

b Do not permit faulty equipment to be operated. Ensure that repairs are carried out competently and checked before students are permitted to operate the equipment.

6 Using Electricity a At least once each month, check that ELCB's (RCCB's) are operating

correctly by pressing the TEST button. The circuit breaker must trip when the button is pressed (failure to trip means that the operator is not protected and a repair must be effected by a competent electrician before the equipment or electrical supply is used).

b Electricity is the commonest cause of accidents in the laboratory. Ensure that all members of staff and students respect it.

c Ensure that the electrical supply has been disconnected from the equipment before attempting repairs or adjustments.

d Water and electricity are not compatible and can cause serious injury if they come into contact. Never operate portable electric appliances adjacent to equipment involving water unless some form of constraint or barrier is incorporated to prevent accidental contact.

e Always disconnect equipment from the electrical supply when not in use.

c

7 Avoiding fires or explosion a Ensure that the laboratory is provided with adequate fire extinguishers

appropriate to the potential hazards. b Where inflammable liquids are used, smoking must be forbidden.

Notices should be displayed to enforce this. c Beware since fine powders or dust can spontaneously ignite under

certain conditions. Empty vessels having contained inflammable liquids can contain vapour and explode if ignited.

d Bulk quantities of inflammable liquids should be stored outside the laboratory in accordance with local regulations.

e Storage tanks on equipment should not be overfilled. All spillages should be immediately cleaned up, carefully disposing of any contaminated cloths etc. Beware of slippery floors.

f When liquids giving off inflammable vapours are handled in the laboratory, the area should be ventilated by an ex-proof extraction system. Vents on the equipment should be connected to the extraction system.

g Students should not be allowed to prepare mixtures for analysis or other purpose without competent supervision.

8 Handling poisons, corrosive or toxic materials a Certain liquids essential to the operation of equipment, for example

mercury, are poisonous or can give off poisonous vapours. Wear appropriate protective clothing when handling such substances. Clean up any spillage immediately and ventilate areas thoroughly using extraction equipment. Beware of slippery floors.

b Do not allow food to be brought into or consumed in the laboratory. Never use chemical beakers as drinking vessels.

c Where poisonous vapours are involved, smoking must be forbidden. Notices should be displayed to enforce this.

d Poisons and very toxic materials must be kept in a locked cupboard or store and checked regularly. Use of such substances should be supervised.

e When diluting concentrated acids and alkalis, the acid or alkali should be added slowly to water while stirring. The reverse should never be attempted.

9 Avoiding cuts and burns a Take care when handling sharp edged components. Do not exert

undue force on glass or fragile items. b Hot surfaces cannot, in most cases, be totally shielded and can produce

severe burns even when not `visibly hot´. Use common sense and think which parts of the equipment are likely to be hot.

d

10 Eye protection a Goggles must be worn whenever there is a risk to the eyes. Risk may

arise from powders, liquid splashes, vapours or splinters. Beware of debris from fast moving air streams. Alkaline solutions are particularly dangerous to the eyes.

b Never look directly at a strong source of light such as a laser or Xenon arc lamp. Ensure that equipment using such a source is positioned so that passers-by cannot accidentally view the source or reflected ray.

c Facilities for eye irrigation should always be available. 11 Ear protection a Ear protectors must be worn when operating noisy equipment. 12 Clothing a Suitable clothing should be worn in the laboratory. Loose garments

can cause serious injury if caught in rotating machinery. Ties, rings on fingers etc. should be removed in these situations.

b Additional protective clothing should be available for all members of staff and students as appropriate.

13 Guards and safety devices a Guards and safety devices are installed on equipment to protect the

operator. The equipment must not be operated with such devices removed.

b Safety valves, cut-outs or other safety devices will have been set to protect the equipment. Interference with these devices may create a potential hazard.

c It is not possible to guard the operator against all contingencies. Use common sense at all times when in the laboratory.

d Before starting a rotating machine, make sure staff are aware how to stop it in an emergency.

e Ensure that speed control devices are always set at zero before starting equipment.

14 First aid a If an accident does occur in the laboratory it is essential that first aid

equipment is available and that the supervisor knows how to use it. b A notice giving details of a proficient first-aider should be prominently

displayed. c A `short list´ of the antidotes for the chemicals used in a particular

laboratory should be prominently displayed.