Inline Refractometer PR-21-S

PROCESS INSTRUMENTS

PROCESSREFRACTOMETERPR-21-S

INSTRUCTIONMANUAL

IM-EN-PR21 Rev. 1.02

PR-21-S instruction manual

INSTRUCTION MANUAL

FOR INLINE REFRACTOMETER

PR-21-S (--GP/FM/IA)

WARNING

The process medium may be hot or otherwise hazardous.

Precautions when removing the sensor from the process line:

Make positively sure that the process line is not under pressure. Open a vent valve to the atmosphere.

For a prism wash system, close a hand valve for the wash medium and disable the wash valve.

Loosen the clamp cautiously, be prepared to tighten again.

Be out of the way of any possible splash and ensure the possibility of escape.

Use shields and protective clothing adequate for the process medium.

Do not rely on avoidance of contact with the process medium.

After removal of the sensor, it may be necessary to mount a blind cover for security reasons.

Document/Revision No. Rev. 1.02 Effective: August 18, 2016

This product manual is delivered to the end user with a K-Patents product.

Information in this manual is subject to change without notice. When the manual is changed, a revised copy is published at

http://www.kpatents.com/.

THE PASSWORD FOR PR-21-S IS 7 8 4 5 1 2.

K-PATENTS OY

Postal address: P.O. Box 77

FI-01511 Vantaa, Finland

Tel. +358 207 291 570

Fax +358 207 291 577

[email protected]

http://www.kpatents.com/

K-PATENTS OY

Street address: Elannontie 5

FI-01510 Vantaa, Finland

K-PATENTS, INC. 1804 Centre Point Circle,

Suite 106,

Naperville, IL 60563

Tel. +1-630-955 1545

Fax +1-630-955 1585

[email protected]


K-PATENTS (Shanghai) Co., Ltd

Room 1509, Tomson

Commercial Building,

No. 710

Dongfang RD, Pudong

District, Shanghai, China

Tel. +86 21 5087 0597/0598

Fax +86 21 5087 0598


Table of contents

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 Standard specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.1.1 Model code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2 Principle of measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.3 General safety considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.4 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.5 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2 Inline refractometer sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.1 Sensor description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.1 Sensor location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.2 Mounting examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.2.3 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.2.4 Wash nozzle for steam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.2.5 Check list for pipe mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

2.2.6 Check list for mounting in a tank, a vessel or a large pipe . . . . . . . . . . . . 18

3 Indicating transmitter DTR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.1 Indicating transmitter description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.2 Mounting Indicating transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.3 Electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.3.1 Interconnecting cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.3.2 Connecting sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.3.3 Connecting the Indicating transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3.3.4 Power terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.3.5 Reset button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4 Prism wash systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.1 Prism coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.2 Prism wash with integral steam nozzle . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.3 Prism wash with integral high pressure water nozzle . . . . . . . . . . . . . . . . . 29

4.4 Prism wash with flow through cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.5 Recommended wash pressures and times . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5 Startup and use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.1 Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.1.1 Initial check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.1.2 Calibration check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.1.3 Testing prism wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.2 Using the Indicating transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.2.1 Keyboard functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

5.2.2 Display setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

5.3 Viewing system information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

5.4 Viewing sensor status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

5.4.1 Optical image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

5.4.2 Diagnostic values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

5.4.3 Temperature measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

5.4.4 Sensor head humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.5 Sensor verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

6 Configuration and calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

6.1 Configuring output signal damping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

6.1.1 Exponential damping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

6.1.2 Linear damping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6.1.3 Slew rate limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6.2 Configuring output signal hold functionality . . . . . . . . . . . . . . . . . . . . . . . . 45

6.2.1 External hold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

6.2.2 Hold during wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

6.2.3 Tolerance time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

6.2.4 QF threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6.2.5 Hold source interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6.2.6 Hold and signal damping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

6.2.7 Hold functions with DD-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

6.3 Configuring relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

6.4 Configuring input switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

6.5 Configuring refractometer system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

6.5.1 Configuring mA outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

6.6 Calibrating the concentration measurement . . . . . . . . . . . . . . . . . . . . . . . . 54

6.6.1 The chemical curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

6.6.2 Selecting display units and display decimals . . . . . . . . . . . . . . . . . . . . . . . 55

6.6.3 Field calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

6.6.4 Entering field calibration parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

6.6.5 Direct BIAS adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

6.7 Configuring prism wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

6.7.1 Wash cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

6.7.2 Setting prism wash parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

6.7.3 Mechanical zero adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

6.7.4 Sensor rangeability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

7 Regular maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

7.1 Checking the sensor humidity level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

7.2 Checking the prism and prism gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

7.3 Disassembling and assembling the sensor . . . . . . . . . . . . . . . . . . . . . . . . . 65

7.3.1 Disassembling the sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

7.3.2 Removing electronic cards PR-10301 and PR-10201 . . . . . . . . . . . . . . . . 67

8 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

8.1 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

8.1.1 Blank display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

8.1.2 Diagnostic LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

8.1.3 Display unreadable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

8.1.4 Message NO SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

8.1.5 Message NO SIGNAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

8.1.6 Message SHORT-CIRCUIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

8.1.7 Message HIGH SENSOR HUMIDITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

8.1.8 Message HIGH SENSOR TEMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

8.1.9 Message HIGH TRANSMITTER TEMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

8.1.10 Message LOW TRANSMITTER VOLT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

8.1.11 Relays and switches not working . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

8.1.12 Output signal error during NORMAL OPERATION . . . . . . . . . . . . . . . . . . . . . . 75

8.2 Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

8.2.1 Message OUTSIDE LIGHT ERROR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

8.2.2 Message NO OPTICAL IMAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

8.2.3 Message PRISM COATED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

8.2.4 Message OUTSIDE LIGHT TO PRISM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

8.2.5 Message LOW IMAGE QUALITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

8.2.6 Message NO SAMPLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

8.2.7 Message TEMP MEASUREMENT FAULT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

8.2.8 Concentration drift during NORMAL OPERATION . . . . . . . . . . . . . . . . . . . 77

8.3 Wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

8.3.1 Message EXTERNAL HOLD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

8.3.2 Messages PRECONDITIONING, WASH, RECOVERING . . . . . . . . . . . . . . . . . . . . . . . 78

8.3.3 Message PRISMWASH FAILURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

8.3.4 Message EXTERNAL WASH STOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

8.3.5 Message LOW TEMP WASH STOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

8.3.6 Message NO SAMPLE/WASH STOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

8.4 Diagnostic messages table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

9 Indicating transmitter DTR specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

9.1 Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

9.1.1 Transmitter program versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

9.2 Model code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

9.2.1 Transmitter model code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

9.2.2 Interconnecting cable model code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

9.3 Transmitter parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

9.4 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

9.4.1 Indicating transmitter specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

9.4.2 Interconnecting cable specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

10 Sensor types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

10.1 PR-21-S part list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

10.2 Sensor PR-21-S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

10.3 Isolation valve with retraction unit (HIMP-2 and HIMP-3) . . . . . . . . . . . . . 90

10.3.1 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

10.4 PR-21-S process refractometers in potentially explosive atmosphere . . . . 96

10.4.1 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

10.5 Intrinsically safe refractometers PR-21-...-IA . . . . . . . . . . . . . . . . . . . . . . . . 97

10.5.1 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

10.5.2 Intrisincally safe mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

10.5.3 Isolator/barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

11 Ethernet connection specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

11.1 Cable requirements and connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

11.1.1 Ethernet cable specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

11.1.2 Connecting the Ethernet cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

11.2 Connection settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

11.2.1 IP settings for DTR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

11.2.2 IP settings for stand-alone computer . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

11.3 Testing the Ethernet connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

PR-21-S instruction manual

11.3.1 Troubleshooting the connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

11.4 Instrument homepage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

11.4.1 Remote panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

11.4.2 Sensor verification certificate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

11.5 Collecting data via Ethernet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

11.5.1 Communication protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

11.5.2 Request-response pair specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

11.5.3 Error message specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

12 Sensor verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

12.1 Refractive index nD verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

12.2 Verification procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

12.3 Sensor verification certificate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

12.4 Corrective action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

13 Regulatory compliance and certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

13.1 EC Declaration of Conformity for PR-21 series of

refractometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

13.2 Declaration of Conformity for PR-21-...-IA models (ATEX) . . . . . . . . . . . . 122

1 Introduction 1

1 Introduction

The K-Patents inline refractometer is an instrument for measuring liquid concentra-

tion in the process line. The measurement is based on the refraction of light in the

process medium, an accurate and safe way of measuring liquid concentration.

The inline refractometer sensor (in Figure 1.1 and Figure 1.2)measures the refractive

index nD and the temperature of the processmedium. This information is sent via the

interconnecting cable to the Indicating transmitter (Figure 1.3). The Indicating trans-

mitter DTR calculates the concentration of the process liquid based on the refractive

index and temperature, taking pre-deined process conditions into account. The out-

put of the DTR is a 4 to 20 mA DC output signal proportional to process solution con-

centration. Process data can also be downloaded to a computer via an Ethernet cable.

Labels on the refractometer tells technical model speciications of the refractometer

(Figure 1.4)

Figure 1.1 Sensor standard, model PR-21-S

2 PR-21-S instruction manual

Figure 1.2 Sensor LPH, model PR-21-S

INSTRUCTION MANUAL FOR K-PATENTS PR-01-S (-AX/FM/CS) DOCUMENT/REVISION No. INM 1/14 Effective: May 15, 2009

3

2. GENERAL INFORMATION

2.1. EQUIPMENT

The K-Patents Process Refractometer consists of three parts (Figure 2.10): the Sensor (A), the Interconnecting Cable (B) and the Indicating transmitter (C). For description of the intrinsically safe K-Patents Process Refractometer, see Chapter 12.

Figure 2.10 Equipment

For intrinsically safe equipment, see Figure 12.10.

The K-Patents Process Refractometer provides a 4 to 20 mA DC output signal proportional to process solution concentration. A serial output is also available as a standard.

Identification: By Serial Number (S/N) label (Figure 2.11) on the Indicating transmitter front panel and by Serial number on sensor label (Figure 2.10, Figure 2.12), e.g. 2003E2C-5604. The sensor type, e.g. 50, is stamped on the probe tip (see Section 2.2.1 for model codes).

PROCESS REFRACTOMETERIT - RE - GP S/N:2003E20-5604100 - 115/220 - 240 V AC, 50/60 Hz, 20VATAG:

Figure 2.11 Identification label, Indicating transmitter.

Figure 2.12 Identification label, Sensor. For intrinsically safe sensor label, see Figures 12.11 and 12.12.

Figure 1.3 Refractometer equipment PR-21-S

PROCESS REFRACTOMETERDTRMGP S/N: T05880100 240 V AC, 50 60 Hz, 30 VATAG:

Dual transmitter label Sensor identification label

Figure 1.4 Labels

1 Introduction 3

1.1 Standard specifications

SPECIFICATIONS

K-PATENTS OYP.O. BOX 77ELANNONTIE 5FI-01511 VANTAA, FINLANDPHONE: INT.+358-207-291 570FAX: INT.+358-207-291 [email protected]

We reserve right to technical alterations.

K-PATENTS, INC.1804 cENTRE POINT cIRcLE, sUITE 106NAPERVILLE, IL 60563 U.s.A.PHONE: (630) 955 1545FAX: (630) 955 [email protected]

Refractive Index range: Low range R.I. 1.320...1.460High range R.I. 1.380...1.530

Max span: R.I. 0.120

Accuracy: Typically 0.1% by weight (depending on the process medium).Repeatability and stability correspond to accuracy.

Speed of response: 1.0 s undamped, damping time selectable up to 5 min

Calibration: With Cargille standard R.I. liquids

Temperature compensation: Automatic, digital compensation

Instrument verification: According to ISO 9000 quality system: with standard R.I. liquids and Transmitter's menu guided procedure

Process temperature: max. 150C (300F) (for higher temp. consult factory)

Ambient temperature: Sensor: max. 45C (113F), min. -20C (-4F) Indicating transmitter: max. 50C (122F), min. 0C (32F)

Process pressure: Flange connections up to 25 bar (350 psi), Sandvik clamp static pressure up to 20 bar (300 psi)/operational pressure up to 10 bar (150 psi)

Sensor protection class: IP65, Nema 4X

SENSOR PR-21-S-STD (STANDARD PROBE) AND PR-21-S-LPL/LPS (LONG PROBE):

Process connection: Sandvik L-clamp, 88 mm; DIN-flange 2656. PN 25, DN80; ANSI-flange, 150 psi, 3inch; ANSI-flange, 300 psi, 3 inch; JIS-flange, 10K 80 A

Process wetted parts: AISI 316L stainless steel, prism gaskets Kalrez (prism pads teflon)

Sensor insertion length: -STD = standard; -LPL = Long probe 302 mm; -LPS = Long probe 150 mm

Sensor weight: Sandvik-clamp 7 kg (15 lbs)/Flange DIN/ANSI/JIS 10.5 kg (23 lbs)

SENSOR PR-21-S-LPH (RETRACTABLE LONG PROBE):

Process connection: Sandvik L-clamp, 88 mm

Process wetted parts: AISI 316L stainless steel, sensor tip SAF2205, prism gaskets Kalrez (prism pads teflon)

Sensor weight: 10.5 kg (23 lbs)

INDICATING TRANSMITTER DTR:

Display: 320x240 pixel graphical LCD with LED backlight

Keypad: 18 membrane keys

Current output: 4-20 mA/0-20 mA, max. load 1000 Ohm, Galvanic isolation1500 V DC or AC (peak), Built-in hold function during prism wash

Ethernet connection: 10/100 Mbit/s, data acquisition over UDP/IP Protocol with K-Patents PR-11111 data logging software

Power: AC input 100-240 VAC/50-60 Hz, optional 24 VDC, 30 VA

Alarms/Wash relays: Two built-in signal relays, max. 240 V AC, 3 A

Sensor connectivity: One or two sensors can be connected to the DTR. Sensors independent of each other: own parameter sets and usable in different applications. Two current outputs configurable independently to indicate process concentration or temperature of either sensor.

Transmitter protection class: Enclosure IP66, Nema 4X

Indicating transmitter weight: 4.5 kg (10 lbs)

INTERCONNECTING CABLE: PR-8230 cable. A paired cable with shielded ground.Screwed connector PR-8031 to connect cable to sensor PR-21-S

Interconnecting cable length: Standard 10 m (33 ft), max. 200 m (660 ft)

OPTIONS: Prism wash, intrinsic safety and hazardous area approvals, cable fittings to

Indicating transmitter DTR

ORDERING INFORMATION: - Sensor type and process connection - Desired scale- Properties of process solution- Process temperature and pressure range

- Process flow range and pipe diameter- Supply voltage and frequency- Length of interconnecting cable- Options and accessories

Sensor PR-21-S with Sandvik clamp

7,9200

0,718

6,3160

DN 80 PN 40

7,3185

0,7519

5,9150

JIS 80A 10k

7,5190,50

0,7519,10

6,0152,40

ANSI 3" 150lbs

8,2209,50

0,8822,30

6,6168,10

ANSI 3" 300lbs

Sheet 2/2

Appr.

DrawnDrawing number

Drawing description

Mass

General tolerances

Revision

BScale

1:3Material

2853

DIMPR-21-S-STD DIN, JIS and ANSI 3" 150lbs or 300lbs flanges

15.08.2013 IA20.08.2013 TL

12.03kg

ISO2768-fK

14,3364

5,9

149,50

5,5139

2,563,50

5,1130

4,7119

Sheet 1/2

Appr.

Drawn

Drawing num

ber

Drawing description

Mass

General tolerances

Revision

BScale

1:2M

aterial

2853

DIM

PR-21-S-STD

DIN

, JIS and AN

SI 3" 150lbs or 300lbs flanges15.08.2013 IA20.08.2013 TL

ISO2768-fK

12.03kg

14,3364

5,9

149,50

5,5139

2,563,50

3,999

4,7119

Appr.

Drawn

Drawing num

ber

Drawing description

Mass

General tolerances

Revision

AScale

1:2M

aterial

DIM

PR-21-S-STD

Sandvik16.08.2013 IA

285720.08.2013 TL

ISO2768-fK

12.03kg

Sensor PR-21-S with ANSI/DIN/JIS flange


1.1.1 Model code

PRELIMINARY

PRICE LIST PR-21-S 1(2)

Area: EURO

Currency: EURO Effective: June 17th , 2013

Replaces:

K-PATENTS OY Postal Address: P.O.Box 77, FI-01511 Vantaa, Finland Street Address: Elannontie 5, FI-01510 Vantaa, Finland

Tel.int.+358 207 291 570 Fax int.+358 207 291 577 [email protected] www.kpatents.com Vat No. FI03035575

Business ID 0303557-5 Registered in Helsinki

K-PATENTS DIGITAL PROCESS REFRACTOMETER PR-21-S A heavy-duty industrial process refractometer model for measuring the liquid concentration of a wide range of chemicals and other liquid phase mediums. Sensor is suitable for process pipe installation and also for tank and reactor installations.

Model and Description Model

PR-21-S = Sensor PR-21-S Refractive Index range limits 50= Low range R.I. 1.320....1.460 50 57= High range R.I. 1.380....1.530 57 Process connection -L = Sandvik L-clamp, 88 mm -L -D = DIN-flange 2656, PN 25, DN 80 -D -A = ANSI-flange 150 psi, 3 inch -A -J = JIS-flange , 10K 80 A -J Sensor wetted parts material SS = AISI 316 L SS XS = AISI 316 L / SAF2205 XS Electrical classification -GP = General purpose -GP -FM = FM Class I, Div.2, Groups A,B,C & D, T6 -FM -IA = ATEX and IECEx certified EX II 1 G Ex ia II C T4 Ga (up to Zone 0) -IA Sensor length -STD = Standard -STD -LPL = Long probe, insertion length 302mm -LPL -LPS = Long probe, insertion length 150mm -LPS Prism wash -HPY = Integral nozzle mounting connection -HPY -HPN = Integral nozzle for water -HPN -HPS = Integral nozzle for steam -HPS -HPX = Integral nozzle for water, drawing number DIM-310/ASAHI -HPX

-YPY = Without integral nozzle mounting connection -YPY

(A) Leave this section blank, code is specified by the Manufacturer according to the Ordering Information Sheet

Model and Description Drawing No. Model

DTR = Indicating Transmitter (connectivity for two sensors) DIM-417 DTR

STR = Indicating Transmitter (connectivity for one IA sensor) DIM-417 STR

Cable connection -U = inch NPT-type conduit hubs -U -M = M20x1,5 metric cable glands -M

Electrical classification - GP = General purpose -GP Transmitter options (B) (leave this section blank, if AC supply is specified) -DC = Power supply 24 V DC -DC

(B) Note standard power supply is 100-240 VAC 50/60 Hz

Part Number and Description Part No.

PR-8230 = Interconnecting cable between transmitter and sensor ( standard black cable) ( for STR transmitter: Interconnecting cable between transmitter and isolator)

PR-8230

Cable length -010 = 10 meters (33 feet), standard length -010 - _ _ _ = Specify cable length in meters with 10 meters increments. Maximum length is 200 meters (660 feet)

-_ _ _

PR-8031 Connector for cable with screw terminals PR-8031

All prices are FCA, Helsinki-Vantaa Airport, Finland. Delivery times are 12 weeks A.R.O. for standard instruments Fill in the Ordering Information Sheet (OIS-PR-21) for each instrument

Figure 1.5 Model code of PR-21-S

1 Introduction 5

PRELIMINARY

PRICE LIST PR-21-S 2(2) Area: EURO Currency: EURO Effective: June 17th , 2013 Replaces:

K-PATENTS OY Postal Address: P.O.Box 77, FI-01511 Vantaa, Finland Street Address: Elannontie 5, FI-01510 Vantaa, Finland Tel.int.+358 207 291 570 Fax int.+358 207 291 577 [email protected] www.kpatents.com Vat No. FI03035575


PROCESS REFRACTOMETER PR-21-S-LPH Model and Description Model PR-21-S = Sensor PR-21-S Refractive Index range limits 50= Low range R.I. 1.320....1.460 max. span R.I = 0.13 50 57= High range R.I. 1.380....1.530 max. span R.I = 0.12 57 Process connection -L = Sandvik L-clamp, 88 mm -L Sensor wetted parts material XS = SAF 2205 / AISI 316L XS Electrical classification -GP = General purpose -GP Sensor length -LPH = Retractable long probe -LPH Prism wash -YPY = Without integral nozzle mounting connection -YPY Parts for off-line calibration check and instrument verification Model and Description Part No. PR-5002 = Sample holder PR-5002 PR-2000 = R.I. liquid set 12 x 1/4 fl.oz. (7 cc) Including R.I. liquids: 1,33; 1,35; 1,36; 1,37; 1,39; 1,41; 1,43; 1,45; 1,46; 1,47; 1.49; 1.50 PR-2000

Figure 1.6 Model code of PR-21-S-LPH

PRELIMINARY

PRICE LIST PR-21-S 3(2) Area: EURO Currency: EURO Effective: June 17th , 2013 Replaces:

K-PATENTS OY Postal Address: P.O.Box 77, FI-01511 Vantaa, Finland Street Address: Elannontie 5, FI-01510 Vantaa, Finland Tel.int.+358 207 291 570 Fax int.+358 207 291 577 [email protected] www.kpatents.com Vat No. FI03035575


Mounting Hardware for Intrinsically Safe IA Sensor Description Part no PR-10910 = IS Isolator ( MTL 5053 Isolator/Power Supply) PR-10910 Enclosure Option -PCE = Polycarbonate enclosure with DIN-rail -PCE Part Number and Description Part No. PR-8260 = Interconnecting cable between isolator and sensor ( I.S. blue cable) PR-8260 Cable length -010 = 10 meters (33 feet), standard length -010 - _ _ _ = Specify cable length in meters with 10 meters increments. Maximum length is 200 meters (660 feet) -_ _ _

Description Part no PR-8250 = Power supply cable between Indicating Transmitter and Isolator PR-8250 Cable length -010 = 10 meters (33 feet), standard length -010 - _ _ _ = Specify cable length in meters with 10 meters increments. Maximum length is 100 meters (330 feet) -_ _ _

Figure 1.7 Model code of PR-21-S-...-IA


1.2 Principle of measurement

The K-Patents Process Refractometer determines the refractive index (R.I) of the

process solution by measuring the critical angle of refraction. The light from a light

source (L) (Figure 1.8) is directed against the interface between a prism (P) and the

process solution (S). The light rays meet this surface at different angles. The relected

rays forman image (ACB),where (C) is the position of the critical angle ray. The rays at

(A) are totally relected at the interface, the rays at (B) are partially relected and par-

tially refracted into the process solution. In this way the optical image is divided into

a light area (A) and a dark area (B). The position of the borderline (C) between the ar-

eas shows the value of the critical angle and thus of the refractive index of the process

solution. The refractive index normally increases with increasing concentration.


7

2.3. PRINCIPLE OF MEASUREMENT

The K-Patents Process Refractometer determines the refractive index (R.I) of the process solution by measuring the critical angle of refraction. The light from a light source (L) (Figure 2.30) is directed against the interface between a prism (P) and the process solution (S). The light rays meet this surface at different angles. The reflected rays form an image (ACB), where (C) is the position of the critical angle ray. The rays at (A) are totally reflected at the interface, the rays at (B) are partially reflected and partially refracted into the process solution. In this way the optical image is divided into a light area (A) and a dark area (B). The position of the borderline (C) between the areas shows the value of the critical angle and thus of the refractive index of the process solution. The refractive index normally increases with increasing concentration.

BC

A

S

P

L

Figure 2.30 Refractometer principle.

Figure 2.31 Optical images.

From this follows that the optical image changes with the process solution concentration as shown in Figure 2.31. The optical image is converted to an electric signal by an image detector.

By this method the concentration of the solution is measured. The color of the solution, gas bubbles or undissolved particles do not interfere with the result.

Figure 1.8 Refractometer principle

2 PR-23 instruction manual

1.2 Principle of measurement

The K-Patents inline refractometer sensor determines the refractive index nD of the

process solution. It measures the critical angle of refraction using a yellow LED light

source with the same wavelength (580 nm) as the sodium D line (hence nD). Light

from the light source (L) in Figure 1.2 is directed to the interface between the prism

(P) and the processmedium (S). Two of the prism surfaces (M) act asmirrors bending

the light rays so that they meet the interface at different angles.

L

P

MM

S

A C B

Figure 1.2 Refractometer principle

The relected rays of light form an image (ACB), where (C) is the position of the critical

angle ray. The rays at (A) are totally internally relected at the process interface, the

rays at (B) are partially relected and partially refracted into the process solution. In

this way the optical image is divided into a light area (A) and a dark area (B). The

position of the shadow edge (C) indicates the value of the critical angle. The refractive

index nDcan then be determined from this position.

The refractive index nDchanges with the process solution concentration and tempera-

ture. When the concentration changes, the refractive index normally increases when

the concentration increases. At higher temperatures the refractive index is smaller

than at lower temperatures. From this follows that the optical image changes with

the process solution concentration as shown in Figure 1.3. The color of the solution,

gas bubbles or undissolved particles do not affect the position of the shadow edge (C).

B BC CA A

Low concentration High concentration

Figure 1.3 Optical imagesFigure 1.9 Optical images

From this follows that the optical image changes with the process solution concentra-

tion as shown in Figure 1.9. The optical image is converted to an electric signal by an

image detector. By this method the concentration of the solution is measured. The

color of the solution, gas bubbles or undissolved particles do not interfere with the

result.

1 Introduction 7

1.3 General safety considerations

The processmediummay be hot or otherwise hazardous. Use shields andprotective

clothing adequate for the process medium - do not rely on avoiding contact with the

process medium.

Precautions when removing a standard sensor from the process line :

Check irst that the process line is depressurized. Open a vent valve to the atmos-phere.

For a prism wash system, close a hand valve for the wash medium and disable thewash valve.

Loosen the lange or the clamp cautiously, be prepared to tighten again.

Ensure you are clear of any possible spillage and you have a clear emergency es-cape path.

After removal of the sensor, itmay be necessary tomount a blind cover for securityreasons.

1.4 Warranty

K-Patents is rigorous in ensuring that all products manufactured and supplied by

K-Patents shall be free of defects inmaterial andworkmanship. K-Patents agrees to ei-

ther replace or repair free of charge any product found to be defective, or parts thereof

when returned to the nearest authorizedK-Patents repair facilitywithin two (2) years

of the products delivery date.

Before returning a defective product for service or replacement, please contact

K-Patents or your nearest K-Patents representative (see http://www.kpatents.com/

for contact information). For the health and safety of personnel handling your return,

clean the instrument, especially the parts that have been in contact with the process

liquid, before packing it. Ship the cleaned instrument to the address given to you.

1.5 Disposal

When wishing to dispose of an obsolete instrument or any parts of an instrument,

please observe local and national regulations and requirements for the disposal of

electrical and electronic equipment. An aluminium or stainless steel sensor housing

can be recycled with other metallic waste of the same type.

2 Inline refractometer sensor 9

2 Inline refractometer sensor

2.1 Sensor description

In the K-Patents Process Refractometer Sensor (Figure 2.1) the measurement prism

(A) is lush mounted in the oblique surface near the tip. The light source (B) is a light

emitting diode.

K-Patents Process refractometer uses a CCD element (C) which has 3648 photocells

in a row integrated on one chip.


8

2.4. SENSOR DESCRIPTION

In the K-Patents Process Refractometer Sensor (Figure 2.40) the measurement prism (A) is flush mounted in the oblique surface near the tip. The light source (B) is a light emitting diode.

K-Patents Process Refractometer uses a digital image detector (C). The image detector consists of 256 photocells in a row integrated on one chip.

A

B

CD

EF G

Figure 2.40 Sensor structure.

The image detector output is a pulse train as shown in Figure 2.41. This number of high pulses corresponds to the position of the shadow edge in the optical image. The number of high pulses is a direct measure of the critical angle. The image digitizer (E) transforms this pulse train to a serial digital signal. This serial signal transmits a package containing a complete description of the optical image and temperature data to the Indicating transmitter.

For automatic temperature compensation, the sensor tip contains a process temperature probe (F).

The digital image sensor (C) is separated from the process heat by fiber optics (D) and the thermal isolation (G). It is housed in the air-cooled sensor head.

a. Optical image

b. Detector window and the photocells

c. Pulse train from the detector.

a

b

c

TIME

V

Figure 2.41 Image detector system.

Figure 2.1 Sensor structure

The image detector output is a pulse train as shown in Figure 2.2. This number of

high pulses corresponds to the position of the shadow edge in the optical image. The

number of high pulses is a direct measure of the critical angle. The sensor processor

card (E) receives the raw data from CCD element (C) and the temperature probe (F).

The digital image sensor (C) is separated from the process heat by iber optics (D) and

the thermal isolation (G). It is housed in the air-cooled sensor head.

a. Optical image

b. CCD element

c. CCD output

V

Figure 2.2 Image detector system


2.2 Mounting

2.2.1 Sensor location

The sensor is deliveredwithmounting guides attached, Figure 2.3 and Figure 2.4. The

sensor is designed for being installed directly in a process line. If the sensor is located

out of doors, somebasic protection against direct exposure to sunlight and rain should

be provided.

Air-cooling

Normally, draught and natural convection provide suficient air cooling. Criteria for

eficient air-cooling:

1. The sensor should be mountedwith the main axis horizontal, Figure 2.4

2. There must be no obstacles for air to low around the sensor head.

3. The sensor cover should not be exposed to high temperature radiation.

If the ambient temperature is higher than 45C (113F) the air-cooling should be im-

provedbyblowing pressurized air against the sensor cover. This is also recommended

when the process temperature is above 110C (230F)when the ambient temperature

is above 35C (95F). The pressurized air can be supplied by the ventilation system.

If no air is available it is possible to wrap a copper coil for cooling water around the

sensor head cover.

Process low conditions

The sensor is designed to make the prism self-cleaning. To ensure a representative

sample and also prism cleaning action, a good process low should be directed against

the prism surface. A low velocity above 1.5 m/s (5 ft/s) is recommended. For lower

velocities prism wash (Section 4) should be considered. Flow velocity is calculated

from v[m/s] = 21.2 * Flow[lit/min]/d[mm]; v[m/s] = 0.125 * Flow[Gpm]/d[in].

Accumulation of sediment or of gas bubbles should be prevented.

If the process pipe vibrates, support the pipe.



2.2.2 PR-23 mounting guide

2 x

4-20

mA

Eth

erne

t

Max

cab

le le

ngth

200

m

Upp

er p

ipe

bend

Dis

play

on

eye-

leve

l

Ext

erna

l mai

n sw

itch

Hig

h ve

loci

ty>1

.5m

/s(>

5ft/s

)

Sm

all d

iam

eter

Hig

h te

mpe

ratu

re

Hig

h te

mpe

ratu

re

Hig

h pr

essu

re

Hig

h pr

essu

re

Eas

y ac

cess

Eas

y ac

cess

Air

cool

ing

PR

-23 m

ounti

ng r

ecom

mendat

ion

1

0 100-

240V

AC

Outs

ide

lig

ht

Figure 2.3 Mounting guide 1/2



20

Figure 3.10 Mounting guide.

Figure 2.4 Mounting guide 2/2


Selection of location

To decide "Where to mount" use the following criteria:

1. Process pipe is preferred to process vessel, because favorable low conditions are

dificult to ensure in a vessel.

2. If the process pipe diameter varies, select the position with the smallest diameter

(and accordingly highest velocity). Then the prismkeeps better clean. If the pipe is

coned up after a pump, valve or magnetic lowmeter, then add a length of straight

pipe before the coning up and mount the refractometer there.

3. If the refractometer is used in a feedback control loop,make the time lag small. E.g.

when a dilution valve is controlled, mount the refractometer as near the dilution

point as possible.

4. If the temperature varies along the process pipe, select the position with the high-

est temperature. Then the risk of prism coating isminimized, because higher tem-

perature means higher solubility and also lower viscosity.

5. Often the position with the highest pressure (= low point in pipe system + after

pump + before valve) has favorable low conditions without sedimentation or air

trapping risks.

6. The sensor should be conveniently accessible for service.

2.2.2 Mounting examples

Formounting drawing for desired pipe diameter and connection type, contact the rep-

resentative of K-Patents or please visit at K-Patents website www.kpatents.com

No special mounting parts are needed tomount K-Patents Process Refractometer. For

all process pipe diameters just a standard piece of 88.9 x 3.6 steel pipe is used as

adapter. For small process pipe diameters the piece of pipe is sealed in the other end

to form a low cell. Examples for different mounting option are given in Figure 2.5

(Sandvik mounting STD, LPL and LPS) and Figure 2.6, Figure 2.7 (Flange mounting).

For langedmounting, the user has to provide the counter lange. For clampmounting

K-Patents provides a weld-on ring. Flow cells can be supplied by K-Patents.


Figure 2.5 Sandvik STD, LPL and LPS


14.3

364

5.9

149.50

5.5139

2.563.50

5.1130

4.7119

20.3

516.50

11.9302

5.5

139

2.563.50

5.1130

10.7

271.50

20.3

516.50

5.9

149.50

5.5139

2.563.50

5.1130

4.7119

STD: DIN, JIS and ANSI 150 lbs or 300 lbs LPL: DIN, JIS and ANSI 150 lbs or 300 lbs

LPS: DIN, JIS and ANSI 150 lbs or 300 lbs

Figure 2.6 Flange STD, LPL and LPS


7.9200

0.718

6.3160

DN 80 PN 40

7.3185

0.7519

5.9150

JIS 80A 10k

7.5190.50

0.7519.10

6.0152.40

ANSI 150lbs

8.2209.50

0.8822.30

6.6168.10

ANSI 300lbs

Sheet 2/2

Appr.

DrawnDrawing number

Drawing description

Mass

General tolerances

20.08.2013 TL Revision Scale

1:3Material

2862

DIMPR-21-S-LPS DIN, JIS and ANSI 150lbs or 300lbs flanges

16.08.2013 IAC

ISO2768-fKFigure 2.7 DIN, JIS and ANSI 150lbs or 300lbs flanges


2.2.3 Mounting

The sensor mounting procedure: (Figure 2.8)

The sensor is connected to the process line.

Identify the sensor by the serial number (a).

Check low direction. If the itting has a ixed lange, the bolt holes should allowproper low alignment of probe. If this is not the case, remove the two ixing bolts

(Figure 10.1 sensor item 2.2). The sensor lange (b) can then be freely rotated.

Save the bolts, they are useful at dismounting or if sensor needs to be sent for

service ixed lange is recommended.

Heat insulate the sensor lange if it can be suspected that a too strong cooling effectcan cause prism coating Section 4.1.

If the process medium is hot and sticky, it is recommended to heat the probe by using

hot water before mounting. A cool prism tends to be rapidly coated.

Figure 2.8 Mounting procedure

2.2.4 Wash nozzle for steam

For mounting of the prism wash systems, see Section 4.


2.2.5 Check list for pipe mounting

Most K-Patents inline refractometer models are mounted in a pipe. K-Patents recom-

mends a minimum low velocity of 1.5 m/s (5 ft/s). The diameter and form of the

pipe and the process temperature all affect the measurement and need to be taken

into account.

1. If the process pipe diameter varies, select the position with the smallest diameter

(and accordingly highest velocity). Then the prism keeps better clean.

2. If the refractometer is used in a feed-back control loop,make the time lag short. E.g.

when a dilution valve is controlled, mount the refractometer close to the dilution

point. However, make sure complete mixing has occurred at mounting location.

3. If the temperature varies along theprocess pipe, select thepositionwith the highest

process temperature. Then the risk of prism coating is minimized, because higher

temperature means higher solubility and also lower viscosity.

4. Often the position with the highest process pressure (= after pump + before valve)

has favorable low conditions without sedimentation or air trapping risks.


2.2.6 Check list for mounting in a tank, a vessel or a large pipe

A probe sensor PR-21-S-...-STD can be inserted with a lange or clamp into tanks and

vessels which either dont have a scraper or where the mixer doesnt touch the vessel

wall.

1. The inserted probe sensor is mounted close to a stirrer to ensure representative

sample of the process liquid and to keep the prism clean.


3. Note that free cooling air should reach refractometer sensor cover.

3 Indicating transmitter DTR 19

3 Indicating transmitter DTR

3.1 Indicating transmitter description

The Indicating transmitter DTR is a specialized computer designed to process data

received from one or two sensors. The Indicating transmitter enclosure (Figure 3.1)

contains a front panel with a backlit Liquid Crystal Display (LCD) and a keyboard. The

front panel swings open to give access for connections and service. Knockout pad-

lock provisions are included in the enclosures both cover latches for locks to prevent

unauthorized access.

PROCESS INSTRUMENTSPROCESS INSTRUMENTS

POWER

Figure 3.1 The Indicating transmitter enclosure

The sensors send the values of the refractive index nD and the process temperature

T to the DTR. The microprocessor system then linearizes the concentration reading

(example in Figure 3.2) and performs an automatic temperature compensation.

10

20

30

40

50

60

70

1.35 1.40 1.45

nD

BRIX

Figure 3.2 A linearized curve


3.2 Mounting Indicating transmitter

The Indicating transmitter should preferably be located in an easily accessible, well

lit and dry area. The enclosure must not be exposed to rain or direct sunlight. Avoid

vibration. Take interconnecting cable length into consideration when choosing the

mounting location.

The enclosure is mounted vertically on an upright surface (wall) using four mounting

feet, see Figure 3.3. The LCD is best viewed when approximately on the eye level of

the user.

Important: Do not drill mounting holes in the enclosure as that will affect the pro-

tection class of the enclosure and damage the electronics.

Figure 3.3 Indicating transmitter: dimensions (mm/in)

and mounting feet measures

Note: The LCD display has an operating temperature range of 050 C and a storage

temperature range of -2060 C.

Important: The DTR does not have a built-in power switch. The system is always

powered on when connected to a power source. K-Patents recommends mounting an

external power switch to control the DTRs power supply, Figure 3.5.

3.3 Electrical connections

3.3.1 Interconnecting cable

Interconnecting cable speciication is in Section 9.4.2 and cable model codes are told

in Section 9.2.2

3.3.2 Connecting sensor

Note that old PR-01-S cables (model codes PR-8001-XXX) can be used if they are in

good shape and shorter than 100 meters.


3.3.3 Connecting the Indicating transmitter

All the electrical terminals of the Indicating transmitter are behind the Front panel.

To access them, irst open the enclosure cover. Then loosen the front panel screw

(Figure 3.4) and swing open the Front panel. All terminals are now accessible.

POWERINDICATORLIGHT

FRONTPANELSCREW

Figure 3.4 Opening the Front panel of the Indicating transmitter

Figure 3.5 The recommended external power switch

! Warning! Check that the power is off before opening the Front panel. If thegreen power indicator light (Figure 3.4) is on, there is still power in the system. To

completely turn off the power, unplug the power supply cord or switch the system off

with an external power switch, (if installed see Figure 3.5).


Figure 3.6 The Motherboard of the Indicating transmitter

Description of the terminals on the H1 interface card PR-10701 and on the Transmit-

ter motherboard PR-10600 (Figure 3.6):

On H1

A 1 2 3 Connection for Sensor A, signal wires (1, 2), cable shield (3).

B 1 2 3 Connection for Sensor B, signal wires (1, 2), cable shield (3).

On Motherboard

11 12 420 mA output 1, positive (11), negative (12), max. load 1000 Ohm, galvanically isolated.

13 14 420 mA output 2, positive (13), negative (14), max. load 1000 Ohm, galvanically isolated.

21 22 Relay 1, one contact output, max. 250 V AC, max. 3 A.

23 24 Relay 2, one contact output, max. 250 V AC, max. 3 A.

31 32 33 Power, L (31), N (32), protective earth (33), 100-240 V AC, 5060 Hz. An external power switch

(Figure 3.5) is recommended.

41 42 24V terminal for DTR internal use only.

Note: Connecting terminal to external 24V supply will void warranty. Connecting external devices

to 24V terminal will void warranty.

51 52 53 54 55 Switch inputs: switch 1 (51), switch 2 (52), switch 3 (53), switch 4 (54) and common (55). A voltage

of 3 V DC is provided over each switch. The switch terminals are galvanically isolated.


3.3.4 Power terminals

The primary AC power is connected to a separate terminal strip 31/32/33 marked

POWER in the lower right-hand corner of the Motherboard (Figure 3.6). The three ter-

minals are marked 31/L, 32/N and 33/PE (protective earth). The power terminal

33/PE is directly connected to the exposed metal parts of the Indicating transmitter

DTR.

3.3.5 Reset button

It is possible to reset and restart both the Indicating transmitterDTRand the sensor(s)

by pushing the reset button. The button is accessed through the cable hole in the

front panel shield (see Figure 3.7 below). You need a thin stick or similar utensil,

preferably of non-conducting material, to reach the reset button. After pressing the

reset button, the display will black out for a few seconds. The instrument will be back

to full operation within 30 seconds.

Resetbutton

Figure 3.7 Location of the reset button

4 Prism wash systems 25

4 Prism wash systems

Three alternatives of prism wash systems can be provided:

Steam wash with integral nozzle, Section 4.2

High pressure water with integral nozzle, Section 4.3

Steam and water wash for low cell mounting, Section 4.4

Inmost of the applications theprismwash is not necessary. However, installing awash

nozzle should always be considered. A prism wash nozzle (Section 4.2, Section 4.3,

Section 4.4) can be useful in cases where normally no prism coating occurs, e.g. to

clean the prism after a process stop using a manual wash valve. Washing can also

be used for operational check (output signal decreases during wash) or as a part of

maintenance schedule. There is a special prism wash nozzle for Isolation and Retrac-

tor Valve HIMP-2 for LPH sensor. See Section 10.3

4.1 Prism coating

Deposit build up on the prism surface disturbsmeasurement. Look out for the follow-

ing indications of coating:

Abnormally high concentration reading or upward CONC

CCD value is getting higher and QF value drops down.

High LED current, especially LED = 100 (max) (See Section 5.4)

Prism wash (see Section 5.1.3) does not change optical image.In most of the applications the prism will keep clean, but if coating occurs, check

the following:

Sensor mounted correctly in respect to low direction (arrow on sensor head).

Suficient low velocity, Section 2.2.1

A temperature difference between process luid and sensor probe may causecoating. This may happen for small lows if the thermal insulation is inade-

quate. In some cases it helps to insulate also the connection lange, Figure 2.4.

If there is a coating problem, it is recommended to try to increase the low velocity, e.g.

by installing a pipe portion with smaller diameter. If this cannot be done, the prism

should be automatically washed at regular intervals, e.g. by steam or hot water. A

prismwash nozzle (Section 4.2) can be useful also in cases without coating problems,

e.g. to clean the prism after a process stop using a manual wash valve.


4.2 Prism wash with integral steam nozzle

Prism wash with integral steam nozzle is for use in applications where steam can re-

move coating from pipe lines. For other applications see Section 4.3 and Section 4.4.

The integral nozzle is mounted on the sensor head (Figure 4.1)

Integral steam nozzle (HPS) can be equipped for a standard length sensor or a long

probe sensor with standard insertion length (LPS) and with the following process

connections:

Sandvik L-clamp, 80 mm

ANSI-lange 150 lbs

DIN lange 2556, PN25, DN 80

JIS lange, 10 K 80A

The earliermentioned sensors are equippedwith an integral nozzle connection (HPY)

as a standard. An integral steam nozzle can be easily itted afterwards, if required.

Figures 4.2 show recommended components for a prism wash system with integral

steam nozzle. The components are provided by K-Patents. The steam line should be

equipped with a check valve (Figure 4.2). If the process medium solidiies at ambi-

ent temperature, the check valve should be insulated (Figure 2.4). A condensate trap

should be used to keep the steam line hot (Figure 4.2).

Alternatively, an external timer can be used. The timer should be equippedwith extra

contact which is kept closed during prism washes.

Note. Do not connect the extra contact to external voltage. For recommended wash

pressures and times see Section 4.5

Note. In Intrinsically Safe system solenoid valves are mounted in the safe area and the

pneumatic valves in hazardous area.



73

Figure 8.21 Mounting of integral steam nozzles with DIN, JIS, ANSI and Sandvik connections. Figure 4.1 Mounting of integral steam nozzles with DIN, JIS, ANSI and Sandvik connections


Figure 4.2 Mounting summary of integral prism wash system

Figure 4.3 Wiring of PR-21-S with DTR


4.3 Prism wash with integral high pressure water nozzle

Integral high pressure water prism wash is recommended to be used in applications

where conventionalwash (Section 4.2) is insuficient to remove coating. It can be used

e.g. in themeasurement of starch, beer worth, green liquor in the wood pulp industry

or directly after the evaporation in the sugar industry.

The Figure 4.4 describes the recommended components for a prismwash systemwith

integral high pressure water nozzle. The components can be supplied by K-Patents.

Note the following items in the high pressure wash system:

Integral water wash nozzle (HPN) is built on a sensor which has a Sandvik clampor a lange connection.

For mounting a low cell see Section 4.4

Check valve PR-3303 is recommended to all washing applications.

The high pressure pump should be able to keep a pressure of 100 bar for a 1.25mm (0.05 in) diameter nozzle.

For recommended wash pressures and times, see Section 4.5 (Table 4.1)

High pressure pump

Use K-Patents PR-3602-SP-400 high pressure pump. K-Patents recommends to use

3(3 phase) pumpswith local voltages. Inletwater temperature should bewarm, about

60 C. K-Patents delivers high pressure pumpwith 8meter rubber high pressure hose.

Customer can also make high pressure line between pump and nozzle from stainless

steel pipes which are suitable for pressures up to 150 bar. With stainless steel pipes

K-Patents recommends to use heat trace and insulation to keep washing water warm

(60-70C).

Warning! Pressure increase can occur in a closed pipe section when the high pres-

sure pump is operated. K-Patents recommends tomount a pressure relief valve in the

pipe section. Relief pressure should be according to pipe pressure rating.

The DTR (Indicating transmitter) relay is used to drive the Power relay unit PR-3603-

400. The Power relay unit drives the high-pressure pump and the water valve. Pump

relay has an overload relay which will switch off the pump if current goes over the

set limit. The coniguration of the Relay is made from the Indicating transmitter key-

board. For the wiring of the high-pressure components, see Figure 4.5


Figure 4.4 Mounting drawing for integral high-pressure wash system


Figure 4.5 Wiring drawing: High-pressure wash system for water


4.4 Prism wash with flow through cells

Figure 4.6 Prism wash with flow through cells



81

Figure 8.41 Flow through cell nozzles. Figure 4.7 Flow through cell nozzles


4.5 Recommended wash pressures and times

To select a recommended wash pressure use the following table:

Nozzle type Wash Wash time Min. above Max. above

medium in seconds process pressure process pressure

Integral nozzles

-HPS steam 2-3 2 bar (30psi) 6 bar (85psi)

-HPN pressure water 10-15 30 bar (450psi) 50 bar (1000psi)

HIMP-2 steam 3-5 2 bar (30psi) 6 bar (85psi)

HIMP-3 water 10-15 30 bar (450psi) 50 bar (1000psi)

Flow cell nozzles

PR-3356/ WP pressure water 10-15 30 bar (450psi) 50 bar (1000psi)

PR-3355/ SN steam 3 2 bar (30psi) 4 bar (70psi)

PR-3354/ WN water 10 2 bar (30psi) 4 bar (70psi)

Table 4.1 Recommended wash pressures and times

Note. Steam wash: Do not use longer wash times than is recommended in the Ta-

ble 4.1

5 Startup and use 35

5 Startup and use

5.1 Startup

5.1.1 Initial check

1. Check the wiring, Section 3.3, Electrical connections.

2. Connect the power. The Power indicator light (Figure 3.4) and the screen should

light up within a few seconds.

3. The Main display should come up on the display, Figure 5.1.

Main display for two sensors Main display for single sensor,

concentration only

Main display for single sensor,

concentration and temperature

Main display for single sensor,

concentration and bar graph

Figure 5.1 Main display alternatives

4. In case the display shows a row of dashes, there is no corresponding sensor (for

example in Figure 5.1, upper left, theres no sensor A, only sensor B is connected).

The diagnostic message is for that sensorNO SENSOR.

5. Check the serial number of the sensor at the upper right corner in the display.

6. For a connected sensor, the diagnostic message at start-up should be NORMAL OPERA-

TION or, if the process pipe is empty, NO SAMPLE. Otherwise, see Section 8.4, Diagnos-

tic messages table.


7. The TEMP value should show the current process temperature.

8. The value and the correct setup of the two mA output signals can be checked by

selecting DESCRIPTION in the Main menu and then mA OUTPUTS in the Description menu

(Section 5.3).

9. If internal relays or switch inputs are used, their settings can also be checked

through the Description menu (Section 5.3).

5.1.2 Calibration check

Wait until normal process conditions occur. The concentration reading is precali-

brated at delivery and a copy of the Sensor calibration certiicate is inside the Indi-

cating transmitter. If the diagnostic message is NORMAL OPERATION but the concentration

reading does not agreewith the laboratory results, then consult Section 6.6, Calibrat-

ing the concentration measurement.

5.1.3 Testing prism wash

1. Check that the steam or water washing parts are connected (Section 4.2).

2. In the Main display, press MENU. Then press 3 (to give the command SENSOR STATUS).

In this Sensor status display by pressing the soft keyWASH. If soft keyWASH does not

appear, no internal relay is conigured for this purpose.

3. Check the nD reading, for a successful wash it must drop below 1.34 during steam

wash and drop to approximately 1.33 during water wash.

Important: Before testing prism wash, check that there is liquid in the pipe in front

of the refractometer sensor.

5.2 Using the Indicating transmitter

The Indicating transmitter DTR receives the refractive index value nD and the process

temperature from the sensor(s). Starting from these values, it calculates the concen-

tration of the process media for display and further transmission. The DTR can also

be programmed to give alarm for high or low concentration. If the refractometer has

a prism wash system, the DTR can control the wash with its built-in timer.

For information on how to use the Indicating transmitter DTR for coniguration and

calibration, see Section 6, Coniguration and calibration.


5.2.1 Keyboard functions

Number keys: The 10 number keys, minus sign, and decimal point are used to enter

numerical parameters. They are also used for menu selections.

ENTER key: The ENTER key is used to implement the selected (highlighted) menu

command or to accept an entered value.

BACK key: The commands are arranged into a decision tree, the BACK key is used to

move one step backward to the preceding display. It is also used to erase or cancel a

numerical input.

Soft keys: Themeaning of the soft key is shown on the display immediately above the

key. Figure 5.2 gives an example the soft key functions, from left to right:

1. SENSOR A: Switch to corresponding menu for Sensor A.

2. Arrow down: Move one step down in the menu.

3. Arrow up: Move one step up in the menu

4. SELECT: Select the highlighted command (equivalent to pressing ENTER).

PROCESSPROCESS INSTRUMENTS

POWER

Figure 5.2 The DTR keyboard and the Main menu for sensor B

Note: Press the key under the display. The display is not touch sensitive.

5.2.2 Display setup

Selecting MENU/MENU A/MENU B or SENSOR A or SENSOR B (depending on your Main display

format) in the Main display gives the Menu display. Choose 4 DISPLAY SETUP to change

the Main display format and bar graph settings, to adjust backlight or contrast and to

invert the display. In DTR program version 2.0 or newer you can also switch between

the existing display languages.


Figure 5.3 Display setup menu

Main display format: As you can see in Figure 5.1, there are four different Main dis-

play formats: the dual sensor format shows information on both sensors while the

three different single sensor formats show selected information on one sensor at a

time. Choose 1MAIN DISPLAY FORMAT in the Display setupmenu to change theMain display.

The current format is shown on the display format selection display, see Figure 5.4 be-

low.

Figure 5.4 Main display format selection.

Note: An automatic 60 s (in veriication 5 min) timeout will make backsteps from

any display until the Main display is reached.

Display appearance: The 2 DISPLAY BACKLIGHT & CONTRAST can be selected from the Display

setup menu (Figure 5.3). The values can be changed by using the arrow soft keys or

alternatively a one digit input, for example 8 designates 80%when adjusting contrast.

The 3 DISPLAY INVERSION contains two choices. The default setting of the display is 1 POS-

ITIVE DISPLAY, i.e. yellow background and black text. However, in some environments

the display may be clearer if 2 NEGATIVE DISPLAY, i.e. black background and yellow text, is

chosen.

Bar graph settings: The command 4 BAR GRAPH allows you to set the bar graph span

and zero separately for sensors A and B.

Note: Bar graph is only visible when Main display is in the bar graph format, see

above.

Display language: The command 5 DISPLAY LANGUAGE lets you choose the DTR display

language from the existing display languages, i.e. the languages that are loaded into

the DTR. The default language is English and it is always available. The order and

number of the languages in the language menu varies depending on what languages

are loaded into the DTR. Language change through this menu is immediate.


5.3 Viewing system information

The DESCRIPTION selection from the Main menu (Figure 5.2) opens a path to complete

information about the system and calibration. This path is risk-free in the sense that

no values can be changed through this menu. To be able to make changes, CALIBRATION

must be selected from the main menu.

The Description menu (Figure 5.5) leads to the following information:

1. SYSTEM: See Figure 5.5, right side.

2. mA OUTPUTS: See Section 6.5.1, Coniguring mA outputs

3. RELAYS: See Section 6.3, Coniguring relays.

4. SWITCHES: See Section 6.4, Coniguring input switches.

5. PRISMWASH: See Sections 6.3 and 6.7, Coniguring prism wash.

6. PARAMETERS: See Section 6.6, Calibrating the concentration measurement.

7. NETWORK: The Ethernet address and card ID of the DTR. See Section 11, Ethernet

connection speciication.

Figure 5.5 System description

5.4 Viewing sensor status

Select SENSOR STATUS at the Main menu.

5.4.1 Optical image

With the image detection algorithm the Optical image graph (See Figure 2.2 for expla-

nation) should look like Figure 5.6, right side. The vertical dotted line indicates the

position of the shadow edge. For empty pipe, the optical image looks like Figure 5.6,

left side. The soft key SLOPE leads to a graph (Figure 5.7) showing the slope (or irst

differential) of the optical image graph in Figure 5.6.

Note: In case there is no signal from the sensor, the image ield is crossed over.

5.4.2 Diagnostic values

The values at the left of the graph are used for diagnostic purposes:

CONC is the inal concentration value including Field calibration adjustment, seeFigure 6.12.

TEMP, see Section 5.4.3. CCD gives the position of the shadow edge on CCD in %.


Empty pipe Normal conditions

Figure 5.6 Typical optical images

Figure 5.7 A slope graph

nD is the refractive index value nD from the sensor. CALC is the calculated concentration value without Field calibration adjustment,

Section 6.6.3

QF or Quality Factor is a value in the range -1000100. It measures the imagesharpness, a typical good value is 50. A QF value below 0 usually indicates prism

coating.

LED is a measure of the amount of light from the light source in%. Should be below100 %.

HD TMP = sensor head temperature, see Section 5.4.3. HD HUM = sensor head humidity, see Section 5.4.4. I_SNS value shows the current to sensor, the nominal value is 40 mA. DTR TMP = Indicating transmitter temperature, see Section 5.4.3. DTR V1 gives the voltage from the power module, the nominal value is 24V. DTR V2 gives the DC supply voltage, the nominal value is 3.3 V.

Note: The Slope display also has a soft key SENSOR RESTARTwhich can be used to restart

the current sensor (see upper left corner of the display for sensor letter) after a sensor

software update.

5.4.3 Temperature measurement

The system contains three different temperature measurements displayed to the left

of the graphs in Figure 5.6:

TEMP is the process temperature used for automatic temperature compensation in the

Indicating transmitter (Section 6.6, Calibrating the concentration measurement).


HD TMP measures the temperature on the Sensor processor card PR-10100 (Fig-

ure 10.2).

DTR TMP measures the temperature on the Motherboard of the Indicating transmitter

(Figure 3.6, The Motherboard of the Indicating transmitter).

Both sensor head temperature and DTR temperature are monitored by the built-in

diagnostics program, see Sections8.1.8, Message HIGHSENSORTEMP, and8.1.9, Message

HIGH TRANSMITTER TEMP.

5.4.4 Sensor head humidity

The Sensor processor card contains also a humidity sensor. The value HD HUM is the

relative humidity inside the Sensor. It is monitored by the diagnostics program, see

Section 8.1.7, Message HIGH SENSOR HUMIDITY.

5.5 Sensor verification

A companymaintaining quality system according to ISO 9000 quality standards must

have deined procedures for controlling and calibrating its measuring equipment.

Such procedures are needed to demonstrate the conformance of the inal product

to speciied requirements. For the recommended veriication procedure, please see

Chapter 12.

6 Configuration and calibration 43

6 Configuration and calibration

All changes of coniguration and calibration are made through the Calibration menu

selected from the Main menu by 5 CALIBRATION.

Password: It may be necessary to enter a password before proceeding to the Calibra-

tion menu. The password is printed on the title page of this manual. The password

function is activated and deactivated via the 6 PASSWORD command in the Calibration

menu. By default the password is activated.

6.1 Configuring output signal damping

The Outputs display also provides the possibility to enter signal damping to diminish

the inluence of process noise. The damping is applied to the CONC value (and thus

the output signal) of the current sensor (see upper edge of the display to check which

sensor is currently chosen and switch in the Outputs display if necessary).

The PR-21-S offers three types of signal damping. The damping parameter is set sep-

arately through the Outputs menu selected from the Calibration menu by 2 OUTPUTS.

What the damping time means in practice, depends on the damping type.

6.1.1 Exponential damping

Exponential (standard) dampingworks formost processes and is the standard choice

for slowand continuousprocesses. The factory setting is always exponential damping,

access the 3 DAMPING TYPE command to switch between different damping algorithms. In

the exponential damping (standard damping), the damping time is the time it takes

for the concentrationmeasurement to reach half of its inal value at a step change. For

example, if the concentration changes from 50% to 60% and damping time is 10 s, it

takes 10 seconds for the DTR to display concentration 55%. A damping time of 515

seconds seems to work best in most cases, the factory setting is 5 seconds. Use the

4 DAMPING TIME menu item to set the damping time. Figure 6.1 shows how exponential

damping time affects the measurement.

0 10 20 30 40 50 60 70 80 90 100 110 120Time [s]

12.0

12.1

12.2

12.3

12.4

12.5

12.6

12.7

12.8

12.9

13.0

CO

NC

[%

] 5 s10 s

20 s

Figure 6.1 Exponential damping


6.1.2 Linear damping

If the process has fast step changes, linear (fast) damping gives shorter settling time.

In the linear damping (fast damping), the output is the running average of the signal

during the damping time. After a step change the signal rises linearly and reaches

the inal value after the damping time. The linear damping gives the best trade-off

between random noise suppression and step change response time. Use the 4 DAMPING

TIMEmenu item to set the damping time. Please note that for similar noise suppression

a longer damping time has to be speciied than for the exponential damping.

Figure 6.2 shows how linear damping time affects the measurement.

0 10 20 30 40 50 60 70 80 90 100 110 120Time [s]

12.0

12.1

12.2

12.3

12.4

12.5

12.6

12.7

12.8

12.9

13.0

CO

NC

[%

] 7 s15 s

30 s

Figure 6.2 Linear damping

6.1.3 Slew rate limit

If the process signal has short erroneous high or low peaks, the slew rate limiting can

be used to cut their effects. The slew rate damping limits the maximum change for

the output signal in one second. It should be noted that the slew rate limit damping is

recommended for random noise suppression as it is non-linear.

The slew rate limit can be set through themenu item 5 SLEW RATE. Typical values depend

on the concentration unit but are typically from0.05% to 1%when the concentration

is measured in percentages. Figure 6.3 gives an example of different slew rate limits.

0 10 20 30 40 50 60 70 80 90 100 110 120Time [s]

52

54

56

58

60

62

64

66

CO

NC

[%

]

0.05 /s

0.2 /s

0.5 /s

Figure 6.3 Slew rate damping


Note: Avoid overdamping, the signal should not be made insensitive.

6.2 Configuring output signal hold functionality

The instrument can be conigured to temporarily hold itsmeasurement result in three

different cases.

1. By using an external hold switch (see Section 6.4)

2. During prism wash (see Section 6.7.2)

3. For a preprogrammed time when there is an intermittent loss of sample on the

prism (due to voids in the process)

When the measurement result is in hold, the displayed concentration value and mA

output do not change. The diagnostic values (e.g. nD) shown on-screen always relect

the actual state of the measurement.

The measurement hold takes place after the CALC value and ield corrections have

been calculated but before the signal iltering (damping) takes place (see Section 6.6).

If the hold is on, the output ilter remains in its earlier state, and the output signal is

stationary. If the hold is started when there is no output signal (e.g. no sample on the

prism), there will be no measurement signal during the hold.

6.2.1 External hold

When a switch input is conigured for external hold functionality (see Section 6.4),

and the switch contact is closed, themeasurement result is in hold. Themeasurement

result is kept in hold until the switch contact is opened. A status message EXTERNAL HOLD

will be shown.

6.2.2 Hold during wash

When the setting "Holdduringwash" (see Section6.7.2) is conigured ACTIVE, theoutput

signal is in hold when the instrument is washing. The signal will be in hold during all

three phases (preconditioning, wash, recovery) of the wash process.

This setting can be used to avoid dips in the measurement signal during the prism

wash.

6.2.3 Tolerance time

The tolerance time setting can be used in processes where there are intermittent

breaks in the measurement due to non-representative sample on the prism. This typ-

ically occurs when there are large voids in the process liquid.

If the optical image can be interpreted, the tolerance time setting does not have any

effect. When the optical image can no longer be interpreted (status messages, e.g., NO

SAMPLE, NO OPTICAL IMAGE, PRISM COATED), the measurement is held for the given number of

seconds.

For example, a setting of 10 seconds ensures that any NO SAMPLE state which is shorter

that 10 seconds will not make a dip into the output signal. The factory setting is 5

seconds, access the 6 TOLERANCE TIMEmenu item to set the tolerance time.


The tolerance time counter is reset always when there is a representative sample on

theprism (e.g., the nD canbedetermined). Figure6.4 illustrates this behaviourwith an

intermittent measurement signal. When the signal drop is shorter than the tolerance

time (e.g. at t = 10 s or t = 35 s in the igure), the output signal does not drop. If the

signal drop is so long that the tolerance time counter reaches zero, there will be a

drop in the output signal (at t = 80 s in the igure)

CO

NC

[%

]

Signal with toleranceOriginal signalFiltered (damped) output

0 10 20 30 40 50 60 70 80 90 100Time [s]

Tol. t

ime c

ounte

r

Figure 6.4 Effect of tolerance time on output

6.2.4 QF threshold

TheQF threshold setting can be used to prevent the instrument frommeasuringwhen

the image quality is below a certain limiting value. When QF value becomes less than

the user deined value the image status changes to NO OPTICAL IMAGE after the user

deined tolerance time (see Section 6.2.3 for tolerance time). By default the QF thresh-

old value is -1000.

6.2.5 Hold source interactions

There are three different reasons why the measurement signal may be in hold. All

three result in the same behaviour, but they also interact with each other.

Wash-related hold (Section 6.2.2) and external hold (Section 6.2.1) are connected in

parallel. If at least one of them is active, the measurement result will be in hold. Tol-

erance time (Section 6.2.3) is independent of these two, but the tolerance timewill be

reset whenever there is another reason for the measurement hold.

For example, if the tolerance time is set to 10 seconds, and wash hold becomes active

after 7 seconds, the remaining tolerance time will be reset to 10 seconds After the

wash is over, there is still 10 seconds of tolerace time remaining.


6.2.6 Hold and signal damping

The signal iltering (damping) is stopped during hold. The last iltered value is shown

on the screen and set to the mA output (if the concentration output is conigured).

Figure 6.5 illustrates this behaviour (gray areas represent the periods when the hold

is active).

0 50 100 150 200Time [s]

40

42

44

46

48

50

52

54

56

58

60

CO

NC

[%

]

Original signalFiltered (damped) output

Figure 6.5 Damping stops during hold

6.2.7 Hold functions with DD-23

The K-Patents Digital Divert Control System DD-23 uses the displayed concentration

value in its decision logic. Due to this, the external hold functionality must not be

used with a DD-23, as it could potentially render the system unsafe by freezing the

measurement result.

The "hold duringwash"must be usedwithDD-23. Otherwise the signal damping com-

binedwith low nD values caused by thewash processmay give erroneous information

to the DD-23 after the wash is over.

The selection of tolerance timewith DD-23 requires a careful risk analysis. The use of

the tolerance time functionality does not slow down the response of the instrument

when the instrument is in NORMAL OPERATION. It does, however, slow down the malfunc-

tion alarm in the DD-23 in case the process pipe becomes empty or some other reason

makes the optical image impossible to interpret. The recommended value for toler-

ance time is 5 seconds when a DTR is used in a DD-23 system.

6.3 Configuring relays

For the electrical properties of the built-in relays, see Section 3.3.3. Each of the two

relays can be conigured individually to either Sensor A or Sensor B, i.e. 02 relays can


be assigned to a sensor. Relays

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Inline Refractometer PR-21-S