Vaisala K-PATENTS PR-21 Series User manual

IM-EN-PR21S-C
User Guide
Process Refractometer
PR-21 Series

PUBLISHED BY
Vaisala Oyj
Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland
P.O. Box 26, FI-00421 Helsinki, Finland
[phone]
Visit our Internet pages at www.vaisala.com.
© Vaisala 2021
No part of this document may be reproduced,
published or publicly displayed in any form or by
any means, electronic or mechanical (including
photocopying), nor may its contents be modified,
translated, adapted, sold or disclosed to a third
party without prior written permission of the
copyright holder. Translated documents and
translated portions of multilingual documents are
based on the original English versions. In
ambiguous cases, the English versions are
applicable, not the translations.
The contents of this document are subject to
change without prior notice.
Local rules and regulations may vary and they
shall take precedence over the information
contained in this document. Vaisala makes no
representations on this document’s compliance
with the local rules and regulations applicable at
any given time, and hereby disclaims any and all
responsibilities related thereto.
This document does not create any legally
binding obligations for Vaisala towards customers
or end users. All legally binding obligations and
agreements are included exclusively in the
applicable supply contract or the General
Conditions of Sale and General Conditions of
Service of Vaisala.
This product contains software developed by
Vaisala or third parties. Use of the software is
governed by license terms and conditions
included in the applicable supply contract or, in
the absence of separate license terms and
conditions, by the General License Conditions of
Vaisala Group.
This product may contain open source software
(OSS) components. In the event this product
contains OSS components, then such OSS is
governed by the terms and conditions of the
applicable OSS licenses, and you are bound by the
terms and conditions of such licenses in
connection with your use and distribution of the
OSS in this product. Applicable OSS licenses are
included in the product itself or provided to you
on any other applicable media, depending on
each individual product and the product items
delivered to you.

Table of contents
1. About this document.......................................................................................7
1.1 Version information.............................................................................................7
1.2 Documentation conventions.............................................................................. 7
1.3 Trademarks...........................................................................................................8
2. Product overview.............................................................................................. 9
2.1 Safety....................................................................................................................11
2.2 Storage conditions, packaging and transportation....................................... 12
2.3 In-line refractometer sensor............................................................................. 12
3. Mounting............................................................................................................. 14
3.1 Choosing sensor mounting location................................................................14
3.2 Mounting examples............................................................................................17
3.3 Mounting sensor.................................................................................................19
3.4 Pipe mounting checklist...................................................................................20
3.5 Checklist for mounting in tank, vessel or large pipe......................................21
4. Indicating transmitter DTR..........................................................................22
4.1 Mounting indicating transmitter......................................................................22
4.2 Electrical connections.......................................................................................23
4.2.1 Interconnecting cable................................................................................ 23
4.2.2 Connecting sensor......................................................................................24
4.2.3 Connecting indicating transmitter............................................................25
4.2.4 Power terminals for AC power................................................................... 31
4.2.5 Power terminals for 24 V DC power.......................................................... 31
4.2.6 Relay connections.......................................................................................32
4.2.7 Reset button................................................................................................34
5. Prism wash systems....................................................................................... 35
5.1 Prism coating.....................................................................................................35
5.2 Prism wash with integral steam nozzle.......................................................... 36
5.3 Prism wash with integral high-pressure water nozzle..................................38
5.4 Prism wash with flow through cells................................................................ 42
5.5 Recommended wash pressures and times.................................................... 43
6. Startup and use............................................................................................... 45
6.1 Startup............................................................................................................... 45
6.1.1 Initial check................................................................................................. 45
6.1.2 Calibration check........................................................................................46
6.1.3 Testing prism wash.....................................................................................46
6.2 Using indicating transmitter............................................................................46
6.2.1 Keyboard functions.................................................................................... 47
6.2.2 Display setup.............................................................................................. 48
6.3 Viewing system information............................................................................50
6.4 Viewing sensor status........................................................................................51
6.4.1 Optical image............................................................................................... 51
6.4.2 Diagnostic values........................................................................................52
6.4.3 Temperature measurement....................................................................... 53
6.4.4 Sensor head humidity................................................................................ 53
6.5 Sensor verification............................................................................................ 53
Table of contents
1

7. Configuration and calibration................................................................... 54
7.1 Configuring output signal damping............................................................... 54
7.1.1 Exponential damping.................................................................................54
7.1.2 Linear damping...........................................................................................55
7.1.3 Slew rate limit..............................................................................................56
7.2 Configuring output signal hold functionality.................................................57
7.2.1 External hold............................................................................................... 58
7.2.2 Hold during wash........................................................................................58
7.2.3 Tolerance time.............................................................................................58
7.2.4 QF threshold................................................................................................59
7.2.5 Hold source interactions............................................................................ 59
7.2.6 Hold and signal damping.......................................................................... 60
7.3 Configuring refractometer system................................................................. 60
7.3.1 Configuring relays...................................................................................... 60
7.3.2 Configuring input switches....................................................................... 62
7.3.3 Configuring mA outputs............................................................................64
7.4 Calibrating concentration measurement....................................................... 66
7.4.1 Chemical curve........................................................................................... 68
7.4.2 Selecting display units and display decimals..........................................68
7.4.3 Field calibration.......................................................................................... 69
7.4.4 Entering field calibration parameters...................................................... 70
7.4.5 Direct BIAS adjustment............................................................................. 70
7.5 Configuring prism wash.................................................................................... 71
7.5.1 Wash cycle....................................................................................................71
7.5.2 Setting prism wash parameters................................................................76
7.5.3 Mechanical zero adjustment......................................................................77
7.6 Sensor rangeability........................................................................................... 78
8. Regular maintenance.....................................................................................79
8.1 Checking the sensor humidity level................................................................79
8.2 Checking the prism and prism gaskets.......................................................... 79
8.3 Disassembling and assembling the sensor.................................................... 79
8.3.1 Disassembling the sensor......................................................................... 80
8.3.2 Removing electronic cards PR-10301 and PR-10201................................81
9. Troubleshooting.............................................................................................. 82
9.1 Hardware............................................................................................................82
9.1.1 Blank display............................................................................................... 85
9.1.2 Diagnostic LEDs..........................................................................................86
9.1.3 Display unreadable.....................................................................................88
9.1.4 Troubleshooting messages....................................................................... 89
9.1.5 Diagnostic message priorities.................................................................. 94
10. Indicating transmitter DTR specifications............................................96
10.1 Compatibility..................................................................................................... 96
10.1.1 Transmitter program versions...................................................................96
10.2 Model code.........................................................................................................97
10.2.1 Indicating transmitter model codes......................................................... 97
10.2.2 Interconnecting cable model code...........................................................97
10.3 Transmitter parts list.........................................................................................98
10.4 Specifications.................................................................................................... 98
10.4.1 Indicating transmitter specifications....................................................... 98
10.4.2 Interconnecting cable specifications..................................................... 100
11. Sensor specifications....................................................................................101
11.1 Model codes...................................................................................................... 101
PR-21 Series User Guide IM-EN-PR21S-C
2

11.2 PR-21-S part list............................................................................................... 103
11.3 Sensor PR-21-S................................................................................................ 105
11.4 Standard specifications.................................................................................. 107
11.5 PR-21-S process refractometers in potentially explosive atmosphere.....108
11.5.1 Equipment................................................................................................. 108
11.6 Intrinsically safe refractometers PR-21-…-IA.................................................110
11.6.1 Equipment....................................................................................................111
11.6.2 Intrisincally safe mounting........................................................................114
11.6.3 Isolator/barriers..........................................................................................116
12. Ethernet connection specification.......................................................... 117
12.1 Cable requirements and connection.............................................................. 117
12.1.1 Ethernet cable specification..................................................................... 117
12.1.2 Connecting Ethernet cable....................................................................... 119
12.2 Connection settings..........................................................................................121
12.2.1 IP settings for DTR..................................................................................... 121
12.2.2 IP settings for stand-alone computer.....................................................122
12.3 Testing Ethernet connection.......................................................................... 123
12.3.1 Troubleshooting connection....................................................................124
12.4 Instrument homepage.....................................................................................125
12.4.1 Remote panel............................................................................................ 126
12.4.2 Sensor verification certificate.................................................................. 127
12.5 Collecting data using Ethernet.......................................................................127
12.5.1 Communication protocol..........................................................................127
12.5.2 Request-response pair specification...................................................... 129
12.5.3 Error message specification......................................................................131
13. Sensor verification........................................................................................ 133
13.1 Refractive index nDverification..................................................................... 133
13.1.1 Handling R.I. liquids.................................................................................. 134
13.2 Verification procedure.................................................................................... 134
13.3 Sensor verification certificate........................................................................ 137
13.4 Corrective action.............................................................................................140
14. Regulatory compliance and certifications..........................................142
14.1 EC Declaration of Conformity for PR-21 series of refractometers.............142
14.2 Declaration of Conformity for PR‑21‑…‑IA models (ATEX)........................ 144
Appendix A: Principle of measurement................................................... 146
Appendix B: PR-21 sensor verification form............................................148
Appendix C: Field calibration form........................................................... 149
Appendix D: DTR command selection tree............................................. 150
Appendix E: STR/Divert mode command selection tree......................151
Warranty........................................................................................................... 153
Technical support........................................................................................... 153
Recycling.......................................................................................................... 153
Table of contents
3

List of figures
Figure 1 Sensor LPH, model PR-21-S............................................................................10
Figure 2 Refractometer equipment PR-21-S.............................................................. 10
Figure 3 Labels.....................................................................................................................11
Figure 4 Sensor structure.................................................................................................12
Figure 5 Image detector system.................................................................................... 13
Figure 6 Mounting guide 1/2........................................................................................... 15
Figure 7 Mounting guide 2/2.......................................................................................... 16
Figure 8 Sandvik LPL and LPS........................................................................................17
Figure 9 Flange LPL and LPS.......................................................................................... 18
Figure 10 DIN, JIS and ANSI 150lbs or 300lbs flanges...............................................19
Figure 11 Mounting procedure........................................................................................20
Figure 12 Indicating transmitter dimensions and mounting feet measures.......23
Figure 13 Wiring of PR-21-S with DTR...........................................................................24
Figure 14 Opening indicating transmitter front panel.............................................. 27
Figure 15 External power switch.....................................................................................28
Figure 16 Motherboard (AC power)...............................................................................29
Figure 17 Motherboard (24 V DC)..................................................................................30
Figure 18 Location of reset button.................................................................................34
Figure 19 Mounting of integral steam nozzles with DIN, JIS, ANSI
and Sandvik connections................................................................................37
Figure 20 Mounting summary of integral prism wash system................................38
Figure 21 Mounting drawing for integral high‑pressure wash system.................40
Figure 22 Wiring drawing: High‑pressure wash system for water..........................41
Figure 23 Prism wash with flow through cells.............................................................42
Figure 24 Flow through cell nozzles...............................................................................43
Figure 25 Main display alternatives................................................................................45
Figure 26 DTR keyboard and Main menu for sensor B..............................................48
Figure 27 Display setup menu......................................................................................... 49
Figure 28 Main display format selection.......................................................................49
Figure 29 System description............................................................................................51
Figure 30 Typical optical images.....................................................................................52
Figure 31 A slope graph.....................................................................................................52
Figure 32 Exponential damping...................................................................................... 55
Figure 33 Linear damping.................................................................................................56
Figure 34 Slew rate damping............................................................................................57
Figure 35 Eect of tolerance time on output.............................................................. 59
Figure 36 Damping stops during hold...........................................................................60
Figure 37 Relay menu for relay 1...................................................................................... 61
Figure 38 Output menu for mA Output 1......................................................................65
Figure 39 Default mA output values..............................................................................66
Figure 40 Concentration calibration layers...................................................................67
Figure 41 Using FIELD SAMPLE soft key...................................................................... 70
Figure 42 Automatic prism wash cycle...........................................................................71
Figure 43 Wash logic.......................................................................................................... 73
Figure 44 Wash cycle..........................................................................................................75
Figure 45 Mechanical zero adjustment..........................................................................78
Figure 46 Sensor rangeability.......................................................................................... 78
Figure 47 Ribbon cable connector.................................................................................. 81
Figure 48 Transmitter card positions............................................................................. 83
Figure 49 Motherboard PR‑10600 and H1 interface card PR‑10701...................... 84
Figure 50 Troubleshooting blank display......................................................................85
Figure 51 Checking power supply.................................................................................. 86
PR-21 Series User Guide IM-EN-PR21S-C
4

Figure 52 Diagnostic LED functions...............................................................................88
Figure 53 Indicating transmitter serial number labels.............................................. 96
Figure 54 Indicating transmitter DTR and STR parts (STR-specific
parts in italics)...................................................................................................98
Figure 55 Probe parts....................................................................................................... 103
Figure 56 Sensor................................................................................................................ 105
Figure 57 Refractometer system PR‑21‑…‑FM............................................................109
Figure 58 FM nameplate................................................................................................... 110
Figure 59 Refractometer system PR‑21‑S‑...‑IA............................................................111
Figure 60 IA nameplate..................................................................................................... 112
Figure 61 Intrinsically safe parts.....................................................................................113
Figure 62 Warning sticker......................................................................................................
Figure 63 Intrinsically safe wiring, PR‑21‑S‑…‑IA........................................................ 115
Figure 64 Isolator unit wiring...........................................................................................116
Figure 65 Connecting DTR to computer.......................................................................117
Figure 66 Connecting DTR to LAN.................................................................................118
Figure 67 Connecting DTR to hub or switch................................................................118
Figure 68 Connecting DTR to WLAN.............................................................................118
Figure 69 Using fiber optics Ethernet........................................................................... 119
Figure 70 Ethernet connector on underside of front panel.....................................121
Figure 71 Typical IP configuration for stand-alone laptop when
connected to DTR; laptop wireless (WLAN) turned o....................... 122
Figure 72 Ping OK.............................................................................................................. 124
Figure 73 Ping error message.........................................................................................124
Figure 74 Instrument homepage open in browser................................................... 126
Figure 75 DTR remote panel........................................................................................... 127
Figure 76 Sample holder: Part number PR‑5002......................................................133
Figure 77 Verification, pre-verificaton checks............................................................135
Figure 78 Verification display......................................................................................... 135
Figure 79 Typical optical images................................................................................... 136
Figure 80 Verification in progress..................................................................................136
Figure 81 Verification completed successfully (here only with one RI liquid).. 137
Figure 82 Instrument verification page open in browser........................................138
Figure 83 Instrument verification certificate..............................................................139
Figure 84 Verification failed............................................................................................140
Figure 85 Finding verification information for sensor verification form............. 141
Figure 86 Refractometer principle................................................................................146
Figure 87 Optical images................................................................................................. 147
Figure 88 Optical image detection................................................................................147
List of figures
5

List of tables
Table 1 Document versions (English)..............................................................................7
Table 2 Recommended wash pressures and times...................................................44
Table 3 Chemical curve parameters..............................................................................68
Table 4 Diagnostic LEDs................................................................................................... 87
Table 5 Hardware troubleshooting................................................................................89
Table 6 Measurement troubleshooting..........................................................................91
Table 7 Wash troubleshooting........................................................................................93
Table 8 Indicating transmitter DTR and STR model codes..................................... 97
Table 9 Interconnecting cable model code................................................................. 97
Table 10 Indicating transmitter specifications..............................................................98
Table 11 Interconnecting cable specifications........................................................... 100
Table 12 PR‑21‑S models....................................................................................................101
Table 13 Transmitter models for 100 … 240 V AC......................................................102
Table 14 Transmitter models for 24 V DC.....................................................................102
Table 15 Cables....................................................................................................................102
Table 16 Standard specifications....................................................................................107
Table 17 Request-response pair specification............................................................ 129
Table 18 Verification results display...............................................................................148
PR-21 Series User Guide IM-EN-PR21S-C
6

1. About this document
1.1 Version information
This document provides instructions for installing, using and maintaining Vaisala K‑Patentsâ
Process Refractometer PR‑21‑S.
Table 1 Document versions (English)
Document code Date Description
IM‑EN‑PR21S, C June 2021 Model codes and specifications updated. Minor structure and style
updates.
IM‑EN‑PR21S, B December 2019 Model codes, specifications updated.
IM‑EN‑PR21S, A September 2019 K‑Patents →Vaisala change, new covers.
1.2 Documentation conventions
Warning alerts you to a serious hazard. If you do not read and follow
instructions carefully at this point, there is a risk of injury or even death.
WARNING!
Caution warns you of a potential hazard. If you do not read and follow
instructions carefully at this point, the product could be damaged or important data
could be lost.
CAUTION!
Note highlights important information on using the product.
Tip gives information for using the product more eciently.
Lists tools needed to perform the task.
Chapter 1 – About this document
7

Indicates that you need to take some notes during the task.
1.3 Trademarks
Vaisalaâand K-PATENTSâare registered trademarks of Vaisala Oyj.
Linuxâis a registered trademark of Linus Torvalds.
Windowsâis either a registered trademark or trademark of Microsoft Corporation in the
United States and other countries.
All other product or company names that may be mentioned in this publication are trade
names, trademarks, or registered trademarks of their respective owners.
PR-21 Series User Guide IM-EN-PR21S-C
8

2. Product overview
The Vaisala K-PATENTSâIn-line Refractometer is an instrument for measuring liquid
concentration 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 in-line refractometer sensor measures the refractive index nD and the temperature of
the process medium, see Figure 1 (page 10). This information is sent through the
interconnecting cable to the indicating transmitter, see Figure 2 (page 10). The indicating
transmitter DTR calculates the concentration of the process liquid based on the refractive
index and temperature, taking pre-defined process conditions into account. The output of
the DTR is a 4 … 20 mA DC output signal proportional to process solution concentration.
Process data can also be downloaded to a computer via an Ethernet cable. The labels on the
refractometer show the technical model specifications of the refractometer, see Figure 3
(page 11).
Chapter 2 – Product overview
9

Figure 1 Sensor LPH, model PR-21-S
Figure 2 Refractometer equipment PR-21-S
PR-21 Series User Guide IM-EN-PR21S-C
10

Model: INDICATING TRANSMITTER
Product code: DTR-U-GP-AC
S/N: T06802
Tag:
100-240 V AC, 50/60 Hz, 30 VA
Made by VAISALA Oyj, Vantaa, Finland
www.vaisala.com IP66
Dual transmitter label
Figure 3 Labels
2.1 Safety
This product has been tested for safety. Note the following precautions:
Only licensed experts may install electrical components. They must
adhere to local and state legislation and regulations.
WARNING!
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 flange or 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.
Wear protective eyewear.
Wear protective gloves.
Chapter 2 – Product overview
11

It is the user’s responsibility to follow manufacturer’s safety and operating instructions. The
client’s organization has the responsibility to develop and maintain occupational safety and
create a safety culture where individuals are expected to follow safety instructions at all
times. Any negligence towards safety instructions or failure to comply with safe practices
should not be tolerated. It is the manufacturer’s responsibility to produce goods that are
safe to use when instructions are followed.
The process medium may be hot or otherwise hazardous. Use shields and protective
clothing adequate for the process medium. Do not rely on avoidance of contact with the
process medium.
2.2 Storage conditions, packaging and
transportation
Soft shell packaging prevents damage to the refractometer. Transport the device in its
original packaging.
Before storing, remove any dirt and grease from the refractometer and make sure that it is
dry.
Storage conditions:
• Temperature: −40 …+40 °С (−40 … +104 °F)
• Humidity: No condensation
2.3 In-line refractometer sensor
The process refractometer sensor is shown in Figure 4 (page 12). The measurement prism
(A) is flush mounted in the oblique surface near the tip. The light source (B) is a light
emitting diode.
The process refractometer uses a CCD element (C) which has 3648 photocells in a row
integrated on one chip.
A
B
C
DE
FG
Figure 4 Sensor structure
PR-21 Series User Guide IM-EN-PR21S-C
12

The image detector output is a pulse train, as shown in Figure 5 (page 13). 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 fiber 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 5 Image detector system
Chapter 2 – Product overview
13

3. Mounting
3.1 Choosing sensor mounting location
The sensor is delivered with mounting guides attached. The sensor is designed to be
installed directly in a process line. If the sensor is located outdoors, protect the sensor
against direct exposure to sunlight and rain.
Air-cooling
Normally, draught and natural convection provide sucient air cooling. Criteria for ecient
air-cooling:
• Mount the sensor with the main axis horizontal, see Figure 7 (page 16).
• Make sure that there are no obstacles for air to flow around the sensor head.
• Make sure that the sensor cover is not exposed to high temperature radiation.
If the ambient temperature is higher than 45 °C (113 °F) the air-cooling should be improved
by blowing pressurized air against the sensor cover. This is also recommended when the
process temperature is above 110 °C (230 °F) and the ambient temperature is above 35 °C
(95 °F). 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 flow conditions
The sensor is designed to make the prism self-cleaning. To ensure a representative sample
and also prism cleaning action, a good process flow should be directed against the prism
surface. A flow 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]/d²[mm]; v[m/s] = 0.125 * Flow[Gpm]/d²[in]. Accumulation of
sediment or of gas bubbles should be prevented. If the process pipe vibrates, support the
pipe.
PR-21 Series User Guide IM-EN-PR21S-C
14

  
 

B




E·)
 @
�---


  
2 x 4-20 mA 100-240
V
AC




 

Figure 6 Mounting guide 1/2
Chapter 3 – Mounting
15

Figure 7 Mounting guide 2/2
PR-21 Series User Guide IM-EN-PR21S-C
16

3.2 Mounting examples
For mounting drawing for desired pipe diameter and connection type, contact your
representative.
No special mounting parts are needed to mount the 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 flow cell. For
examples of dierent mounting options, see Figure 8 (page 17), Figure 9 (page 18), and
Figure 10 (page 19).
For flanged mounting, the user has to provide the counter flange. For clamp mounting
Vaisala provides a weld-on ring. Flow cells can be supplied by Vaisala.
Figure 8 Sandvik LPL and LPS
Chapter 3 – Mounting
17

2 0.3
51 6.50
11.9
302
5.5
139
2.5
63.50
5.1
130
10.7
271.50
LPL: DIN, JIS and ANSI 150 lbs or 300 lbs
20.3
516.50
5.9
149.50
5.5
139
2.5
63.50
5.1
130
4.7 119
LPS:DIN, JIS and ANSI 150 lbs or 300 lbs
Figure 9 Flange LPL and LPS
PR-21 Series User Guide IM-EN-PR21S-C
18