Vaisala GMP343 User Manual

USER’S GUIDE
Vaisala CARBOCAP® Carbon Dioxide
Probe GMP343
M210514EN-E
PUBLISHED BY
Vaisala Oyj Phone (int.): +358 9 8949 1 P.O. Box 26 Fax: +358 9 8949 2227 FI-00421 Helsinki Finland
Visit our Internet pages at www.vaisala.com
No part of this manual 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 manuals 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 manual are subject to change without prior notice.
This manual 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.
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Table of Contents

CHAPTER 1
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Contents of This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Version Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Documentation Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
ESD Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Regulatory Compliances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
CHAPTER 2
PRODUCT OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Introduction to GMP343 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
GMP343 Transmitter Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
User Configurable CO2 Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Principle of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Optics Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Gas Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Diffusion Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Flow-Through Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Sampling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Soil Adapter Kits for In-Soil Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
MI70 Indicator Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Recharging the Battery Pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Structure of the MI70 Indicator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Using MI70 as a Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Introduction of Function Keys and Menu Structure. . . . . . . . . . . . . . . . . . . . . 20
Initialization of MI70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Navigation in Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Using MI70 in Recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Transferring Recorded Data to PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
CHAPTER 3
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Wiring of the Junction Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
VAISALA________________________________________________________________________ 1
________________________________________________________________________________
CHAPTER 4
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Connecting GMP343 to PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Connection Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Installing the Driver for the USB Cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Opening a Terminal Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Operation modes of the GMP343 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Getting the Measurement Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Measurement Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Starting the Continuous Outputting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Stopping the Continuous Outputting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Setting the Continuous Outputting Interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Outputting the Reading Once . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Setting the Serial Interface Measurement Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Setting Communication Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Serial Communication Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Formatting the Measurement Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Formatting the Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Setting Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Networking Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Setting the Transmitter Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Open and Close . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Setting Echoing Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Preparation for Network Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Commands during Network Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Measurement Range, Data Filtering and Linearization . . . . . . . . . . . . . . . . . . . . . . . 40
Setting the Measurement Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Measurement Data Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Median Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Averaging Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Smoothing Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
How the Filtering Affects the Response Time . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Setting the Median Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Setting the Averaging Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Setting the Smoothing Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Flushing the Filters (Resynchronization) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Linearization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Setting the Linearization ON/OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Temperature, Pressure, Relative Humidity, and Oxygen Compensations . . . . . . . . 45
Temperature Compensation ON/OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Setting the Oxygen Concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Setting Oxygen When the Device Is in POLL-mode. . . . . . . . . . . . . . . . . . . . . . . 48
Oxygen Compensation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Setting the Ambient Pressure (hPa) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Setting Pressure When the Device Is in POLL-mode. . . . . . . . . . . . . . . . . . . . . . 49
Pressure Compensation ON/OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Setting Ambient Relative Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Setting Humidity When the Device Is in POLL-mode . . . . . . . . . . . . . . . . . . . . . . 50
Relative Humidity Compensation ON/OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Setting and Testing the Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Analog Output Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Setting the Limit of the Current Output Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Setting the High Limit of the Voltage Output Range . . . . . . . . . . . . . . . . . . . . . . . . . . 53
2 _______________________________________________________________________________
________________________________________________________________________________
Setting the High Limit of the Concentration Range . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Setting the Low Limit of the Concentration Range . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Setting the Analog Output Overrange Clip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Testing the Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Setting the Analog Output Error Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Device Information and Other General Commands . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Device Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Show the Output Quantities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Linear and Multipoint Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Command List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Showing the Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Software Version Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Memory Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Reverting the Factory Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Saving the Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Setting the Optics Heating ON/OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Resetting the Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
CHAPTER 5
CALIBRATION AND ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Calibration Interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Factory Calibration and Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Calibration and Adjustment by the User . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Calibration (Checking) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Checking the Compensations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Measurements in Reference Gases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Adjustment in 1...2 Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Adjustment in 3...8 Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Example of the 2-Point Adjustment Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . 65
CHAPTER 6
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Cleaning the Probe Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Changing the Filter and Cleaning the Optics (Diffusion Model Only) . . . . . . . . . . . 70
Error States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Product Returns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
CHAPTER 7
TECHNICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Effects of Temperature, Pressure, Relative Humidity, and Oxygen . . . . . . . . . . . . 76
Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Response time (90 %) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
VAISALA________________________________________________________________________ 3
________________________________________________________________________________
Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Spare Parts and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
APPENDIX A
DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
GMP343 (Flow-through) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
GMP343 (Diffusion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Calibration Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Mounting Flange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Junction Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Mounting Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
APPENDIX B
LIST OF COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Measurement Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Filtering Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
P, T and RH Compensation Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Device Handling Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Device Information Display Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Calibration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Setting and Testing the Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Advanced Measurement Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
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List of Figures
Figure 1 Two Models of GMP343 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 2 Principle of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 3 Components of the Sampling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 4 Examples of Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 5 Structure of the MI70 Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 6 Keyboard of MI70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 7 Mounting GMP343 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 8 Entering Measurement Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 9 The Difference of the Two Filters in Time Response . . . . . . . . . . . . . . . . . 43
Figure 10 Opening the Diffusion Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Figure 11 Optics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Figure 12 GMP343 Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
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List of Tables
Table 1 Manual Revisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Table 2 Wiring Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 3 Communication Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 4 Quantities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 5 Modifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 6 Averaging Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 7 Troubleshooting Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Table 8 Effect of Temperature on Accuracy with Temperature Compensation . . . . 76
Table 9 Effect of Pressure on Accuracy with Pressure Compensation . . . . . . . . . . 76
Table 10 Diffusion Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Table 11 Flow-through Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Table 12 List of Spare Parts and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
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8 _______________________________________________________________________________
Chapter 1 ________________________________________________________ General Information
CHAPTER 1
GENERAL INFORMATION
This chapter provides general notes for the manual and the product.

About This Manual

This manual provides information for installing, operating, and
maintaining the Vaisala CARBOCAP® Carbon Dioxide Probe GMP343.

Contents of This Manual

- Chapter 1, General Information: This chapter provides general notes for the manual and the product.
- Chapter 2, Product Overview: This chapter introduces the features of the GMP343.
- Chapter 3, Installation: This chapter provides you with information that is intended to help you install this product.
- Chapter 4, Operation: This chapter contains information that is needed to operate the GMP343.
- Chapter 5, Calibration and Adjustment: This chapter contains information for performing the calibration and adjustment of the GMP343.
- Chapter 6, Maintenance: This chapter instructs in the basic maintenance of the GMP343.
- Chapter 7, Technical Data: This chapter provides the technical data of the GMP343.
- Appendix A, Dimensions: This appendix contains the dimension drawings for the GMP343.
- Appendix B, List of Commands: This appendix lists the serial commands of the GMP343.
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Version Information

Table 1 Manual Revisions
Manual Code Description
M210514EN-E November 2013. This manual. Updated probe
cleaning instructions.
M210514EN-D June 2013. Previous version. Updated
temperature dependence specification. Updated Technical Support contact information and warranty information.

Documentation Conventions

Throughout the manual, important safety considerations are highlighted as follows:
WARNING
CAUTION
NOTE
Warning alerts you to a serious hazard. If you do not read and follow instructions very carefully at this point, there is a risk of injury or even death.
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.
Note highlights important information on using the product.

ESD Protection

Electrostatic Discharge (ESD) can cause immediate or latent damage to electronic circuits. Vaisala products are adequately protected against ESD for their intended use. However, it is possible to damage the product by delivering electrostatic discharges when touching, removing, or inserting any objects inside the equipment housing.To make sure you are not delivering high static voltages yourself handle ESD sensitive components on a properly grounded and protected ESD workbench. When this is not possible, ground yourself to the equipment chassis before touching the connections. Ground yourself with a wrist strap and a resistive connection cord. When neither of the above is possible, touch a conductive part of the equipment chassis with your other hand before touching the boards.
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Recycle all applicable material.
Dispose of batteries and the unit according to statutory regulations. Do not dispose of with regular household refuse.

Recycling

Trademarks

CARBOCAP® is a registered trademark of Vaisala Oyj.

Regulatory Compliances

Vaisala CARBOCAP® Carbon Dioxide Probe GMP343 is in compliance with the following EU directive, including the latest amendments, and with national legislation implementing this directive:
- EMC-Directive
Conformity is shown by compliance with the following standards:
- EN 61326-1: Electrical equipment for measurement, control, and laboratory use - EMC requirements - Generic Environment.
- CISPR16/22 class B, EN 61000-4-2, EN 61000-4-3, EN 61000-4-4, EN 61000-4-5, EN 61000-4-6.

Warranty

Visit our Internet pages for more information and our standard warranty terms and conditions: www.vaisala.com/warranty.
Please observe that any such warranty may not be valid in case of damage due to normal wear and tear, exceptional operating conditions, negligent handling or installation, or unauthorized modifications. Please see the applicable supply contract or Conditions of Sale for details of the warranty for each product.
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CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces the features of the GMP343.

Introduction to GMP343

Vaisala CARBOCAP® Carbon Dioxide Probe GMP343 is designed for high accuracy CO2 measurements. The measurement is based on the
advanced CARBOCAP® Single-Beam Dual-Wavelength NDIR technology. GMP343 consists of a CO2 sensor, electronics, and a housing
suitable for long-term outdoor use.There are two GMP343 models available: a flow-through model and a diffusion model. One adjustable analog output can be configured to output voltage or current signal (0 ...
2.5 V, 0 ... 5 V, 4 ... 20 mA). A digital output for RS-232/RS-485
communication is available. The measuring range options vary from 0 ... 1000 ppm to 0 ... 2 %CO
Each GMP343 is calibrated using ±0.5 % accurate gases at 0 ppm, 200 ppm, 370 ppm, 600 ppm, 1000 ppm, 4000 ppm and 2 %. Calibration is also done at temperature points of -30 °C, 0 °C, 25 °C and 50 °C. If needed, the customer can recalibrate the instrument using the multipoint calibration (MPC) feature allowing up to 8 user-defined calibration points.
The GMP343 can be ordered with various adapter, filter, and connection cable options. For a list of spare parts and accessories, see section Spare
Parts and Accessories on page 80.
.
2
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GMP343 Transmitter Components

Figure 1 Two Models of GMP343
The following numbers refer to Figure 1 above. 1 = Filter 2 = Wiring connector 3=Gas in 4 = Gas out 5 = Back flange (do not open)
NOTE
Warranty is void if the back flange of the GMP343 has been opened by the user.

User Configurable CO2 Measurement

The measurement output of the GMP343 is user configurable. You may have the raw data without filtering or compensation, or you may set the filtering levels, enable compensation (pressure, temperature, relative humidity, and oxygen) and linearization.
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You can also select the measurement range to optimize the performance of the GMP343 for a certain concentration level. Selecting an appropriate measurement range increases accuracy, since it enables the range-specific compensation and linearization settings. For more information, see sections Setting the Measurement Range on page 40 and Temperature,
Pressure, Relative Humidity, and Oxygen Compensations on page 45.

Principle of Operation

The infra-red sensor of GMP343 is based on the proprietary Vaisala
CARBOCAP® sensing technology. Here the pulsed light from a miniature filament lamp is reflected and re-focused back to an IR detector which is behind a silicon-based Fabry-Perot Interferometer (FPI). This tiny FPI is tuned electrically so that its measurement wavelength is changed between the absorption band of the CO
gas and a reference band.
2
Figure 2 Principle of Operation
When the passband of the FPI coincides with the absorption wavelength of the CO
gas, the IR detector sees a decrease in the light transmission. The
2
measurement wavelength of the FPI is then changed to the reference band (that has no absorption lines) and the IR detector sees a full light transmission. The ratio of these two signals indicates the degree of light absorption in the gas and is proportional to the gas concentration. It takes 2 seconds to measure this sequence and to calculate one reading.
Use of numerical filtering reduces the noise of the raw data. On the other hand, the filtering increases the response time of the device (see Figure 9
on page 43).
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Optics Heating

Two heating elements are placed in the optics; one behind the mirror and one behind the window of the sensor. Heating should always be turned on when there is a risk of dew formation on the optics surface. The heating maintains the surface temperature of the optics a few degrees above the ambient temperature.
The heating is disabled by default. For instructions on how to control the optics heating, refer to section Setting the Optics Heating ON/OFF on page
60.
NOTE
The optics heating is automatically disabled when you connect the GMP343 to a MI70 indicator.

Gas Sampling

There are two GMP343 models available: a flow-through model and a diffusion model.

Diffusion Sampling

No sampling system is needed with the GMP343 diffusion model. The diffusion filter and the plastic filter cover protect the measuring chamber from dirt, water, and contaminants.
In order to have a quick measurement with very short response time the filter can be removed; see section Response time (90 %) on page 77. In this case the optics are openly exposed to contamination and cleaning of optics may be necessary more often. For instructions on cleaning the optics, refer to section Changing the Filter and Cleaning the Optics (Diffusion Model
Only) on page 70. Removal of the filter is not recommended if there is a
risk of getting water or dirt particles on the optics.

Flow-Through Sampling

The maximum gas flow rate is 10 liters/min. When using high flow rates, please note how the flow rate affects the accuracy, see Specifications
Response time (90 %) on page 77 (flow dependence). The volume of the
internal measurement chamber is 59 ml ± 1 ml.
The gas sample must not include acidic gases.
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CAUTION
Liquids or acidic vapors may seriously damage the sensor.

Sampling System

The GMP343 flow-through model has no diffusion filter inside the measuring chamber and the optics of the flow-through model cannot be cleaned by the user. Therefore the sample gas must always be filtered and dried before it is pumped to the measuring chamber. A hydrophobic diffusion filter before the inlet of the measuring chamber is needed in order to prevent particles and water from the surroundings from getting into the sensor. The diffusion filter needs to be exchanged often enough to provide a sufficient flow.
In humid environments it is important to avoid water condensation inside the measuring chamber. This can be avoided by drying the sample air. The most common method of drying the sample air is cooling and re-heating the air. A simple system may consist for example of a cooling coil and a water trap which are either cooled or located in a cool environment, followed by a re-heating system. The idea is to get the moisture in the sample to condensate on the walls of the copper tube, trap this water and then lower the relative humidity by heating the sample. If the temperature inside the measurement chamber is essentially higher than the surroundings the cooling coil and the water trap can be simply located outside the chamber. For re-heating, the heat generated by a pumping system may sometimes be adequate, meaning that no additional heater is needed. A simplified schema of a sample system removing particles and moisture is illustrated below.
All sampling system components are commercially available.
Figure 3 Components of the Sampling System
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Optional Accessories

Various adapter and filter options are available for the GMP343. For a complete list, see section Spare Parts and Accessories on page 80.
Figure 4 Examples of Optional Accessories

Soil Adapter Kits for In-Soil Applications

The vertical/horizontal soil adapter kit consists of a soil adapter and a hydrophobic sintered PTFE filter. The kits are designed for in-soil CO2
measurements to be used with the diffusion model of GMP343.

MI70 Indicator Connection

Vaisala MI70 indicator is an optional accessory to be used as a display, communication, and data-logging device for GMP343. When taking measurements the GMP343 is powered via MI70.
The following accessories are included when the MI70 indicator is ordered with the GMP343:
- Rechargeable battery pack.
- AC recharger with Euro, UK, US, and AUS adapters.
- MI70Link software with RS-232 cable (PC <–> MI70).
- 2 m interface cable (GMP343 <–> MI70).
Recharging the Battery Pack
The rechargeable battery pack is located behind the back plate of the indicator. Recharge the battery pack as follows:
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1. Plug in the recharger connector into the connector on top of the indicator and connect the recharger to a wall socket. A battery symbol in the corner of the display starts to roll.
- It is not recommended to use MI70 during the first recharging.
Later on MI70 can be used while recharging.
- Duration of recharging depends on the charge level of the battery
pack being 4 hours typical. The recommended first recharging time is 6 hours.
2. The battery pack is full when the battery symbol in the display stops rolling.
3. Disconnect the recharger.
Structure of the MI70 Indicator
Figure 5 Structure of the MI70 Indicator
The following numbers refer to Figure 4 above: 1 = Recharging connector 2 = Power On/Off key 3 = Connection cable (DRW216050SP) for GMP343 connection
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Using MI70 as a Display
Introduction of Function Keys and Menu Structure
NOTE
0704-034
Figure 6 Keyboard of MI70
The following numbers refer to Figure 6 on page 20: 1 = Function keys left/middle/right (can be assigned to shortcuts) 2 = Arrow keys up/down/left/right 3 = Power on/off key
Initialization of MI70
The optics heating is automatically disabled when you connect the GMP343 to the MI70 indicator.
1. Install the connection cable between MI70 and GMP343 (GMP343 is powered from MI70).
2. Turn on MI70 by pressing the Power On/Off key.
3. Select the language by using the up/down arrow keys. Confirm by pressing the SELECT key.
4. To change the date, select Date and press the SET key. Set the date by using the up/down/left/right arrow keys. To confirm the date, press the OK key.
5. To change the time, select Time and press the SET key. Set the time by using the up/down/left/right arrow keys. To confirm the time, press the OK key.
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6. To check and change the environment settings, select YES. Enter ambient pressure, humidity, and oxygen values. Press the EXIT key.
Navigation in Menu
- To turn the indicator on or off, press the Power On/Off key.
- To open the main menu, press any of the arrow keys and then the middlemost function key in sequence.
- To move in a menu and select an option, press the up/down arrow keys. To enter sub-menu of selected option, press the right arrow key. To return to the previous menu level, press the left arrow key.
- To activate a function: press a function key according to the guiding text below the key.
- To return to the basic display directly from any menu levels, press the function key EXIT.
The main settings are found in the following menu locations:
- To change language, enter: Settings - User interface - Language.
- To select display quantities (carbon dioxide and temperature), enter: Display - Quantities and units. The carbon dioxide concentration is shown in ppm or in %-units and temperature in °C or °F.
- To set the ambient conditions enter Environment menu. The default settings are: 1013 hPa, 50 %RH, and 20.9 %O2.
Using MI70 in Recording
Record continuous measurement data and view the recorded data by using the MI70. This function is found from the menu RECORDING/
VIEWING.
You can switch MI70 off during recording to save battery power. Display message tells you that recording continues undisturbed even when the power is off. If the indicator is switched off during recording, the progress bar is shown on the display every 10 seconds (all the time, if the charger is connected). This bar shows the amount of recorded data.
Save individual measurement data points with Hold/Save function (DISPLAY-HOLD/SAVE DISPLAY) and view the saved data from the RECORDING/VIEWING menu.
CAUTION
Do not disconnect the probe when the data recording is on, even if the indicator is off. This may cause loss of recorded data.
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Transferring Recorded Data to PC
The recorded data can be transferred to a PC by using MI70 Link program. MI70 Link program can be ordered from Vaisala, see Table 12 on page 80. You can examine the recorded data easily in Windows and transfer it
further to a spreadsheet program (such as Microsoft® Excel) for modification.
More information on the data transfer and software features is found in the online help of the MI70 Link program.
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CHAPTER 3
INSTALLATION
This chapter provides you with information that is intended to help you install this product.

Mounting

A horizontal mounting position is recommended in order to minimize the problems caused by possible condensation.
0704-020
Figure 7 Mounting GMP343
1. Fasten the GMP343 to the mounting bracket by using the screw provided.
2. Mount the mounting bracket with 4 screws (on corners of the plate).
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Wiring

As it is shipped from the factory, the measurement range and output of the GMP343 are scaled according to the order form completed by the customer. The unit is calibrated at the factory. The device is ready for use when the wiring is done and power is switched on.
GMP343 can be connected to a PC using an optional PC connection cable, see Table 12 on page 80.
For more information on serial commands, see Chapter 4, Operation, on
page 27.
WARNING
Make sure that the main power is switched off before making any electrical connections.
Table 2 Wiring Pins
Pin Wire Serial signal (RS-232 or 2-
Wire RS-485 interface)
1 White RS232C: TX RS485: A(+) ­2 Brown RS232C: TX RS485: A(+) ­3 Green RS232C: RX RS485: B(-) ­4 Yellow - - Signal + 5 Grey Supply GND Supply GND Supply GND 6 Pink +11...36 V DC +11...36 V DC +11...36 V DC 7 Blue RS232C: RX RS485: B(-) ­8 Shield - - Signal GND
24 ___________________________________________________________________M210514EN-E
Analog signal
Chapter 3 _______________________________________________________________ Installation
There are two pins per signal internally hardwired in parallel (pins 1 and 2, pins 3 and 7). You should connect the RS-232C signal 'TX' (or 2-Wire RS­485 signal 'A') either to the pin 1 or 2 and the RS-232C signal 'RX' (or 2­Wire RS-485 signal 'B') either to the pin 3 or 7.
Note that there is either an RS-232 or a 2-wire RS-485 communication interface available according to initial configuration. However, if the device is configured in RS-485 output mode, the device can still be switched into RS-232 mode by re-configuration via PC. For more information on serial commands and RS-232/485 modes, see Chapter 4,
Operation, on page 27.

Wiring of the Junction Box

The optional 8-pole junction box enables practical in-line connection. The box is provided with 8 numbered terminals.
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CHAPTER 4
OPERATION
This chapter contains information that is needed to operate the GMP343.

Connecting GMP343 to PC

Connection Cables

To connect the GMP343 to a PC, you need the PC Connection Cable (optional accessory 213379). If your PC does not have a serial port, you also need the USB-D9 Serial Connection Cable (optional accessory
219686). By connecting the two cables, you can use a standard type A USB
port to connect the GMP343 to a PC.
Both cables are included in the PC Connection Kit that can be ordered with the GMP343.
Installing the Driver for the USB Cable
Before taking the USB cable into use, you must install the provided USB driver on your PC.
1. Check that the USB cable is not connected. Disconnect the cable if you have already connected it.
2. Insert the media that came with the cable, or download the latest driver from www.vaisala.com.
3. Execute the USB driver installation program (setup.exe), and accept the installation defaults. The installation of the driver may take several minutes.
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4. After the driver has been installed, connect the USB cable to a USB port on your PC. Windows will detect the new device, and use the driver automatically.
5. The installation has reserved a COM port for the cable. Verify the port number, and the status of the cable, using the Vaisala USB Instrument Finder program that has been installed in the Windows Start menu. The reserved ports are also visible in the Ports section of the Windows Device Manager.
Remember to use the correct port in the settings of your terminal program. Windows will recognize each individual cable as a different device, and reserve a new COM port.
There is no reason to uninstall the driver for normal use. However, if you wish to remove the driver files and all Vaisala USB cable devices, you can do so by uninstalling the entry for Vaisala USB Instrument Driver from the Programs and Features menu in the Windows Control Panel. In Windows XP and earlier Windows versions the menu is called Add or Remove Programs.

Opening a Terminal Connection

The communication interface of GMP343 is RS-232 or RS-485. In case your device is configured to RS-485 communication mode you can still start communication in RS-232 mode (for example when changing the probe setting). See step number 4 in the following instructions.
1. Connect the GMP343 to the PC using the connection cable(s). Refer to section Connection Cables on page 27.
2. Connect the power cables to a 11 ... 36 V power supply.
3. Open a terminal program and set the communication parameters. When using the terminal session for the first time, save the settings for future use.
Table 3 Communication Parameters
Parameter Value
baud rate 19200 parity no data bits 8 stop bits 1 flow control none
4. Power-up the GMP343. The device should prompt as follows:
GMP343 - Version STD 2.0
Copyright: Vaisala Oyj 2003 - 2006
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5. If your device is configured to RS-485 communication mode, switch the device into the service mode by sending a string containing at least 6 capital 'Z' while powering up. The most convenient way using PC is:
Press and keep pressing SHIFT + 'z' while powering up GMP343. Keep pressing SHIFT + 'z' until GMP343 starts up in the service mode. The device should prompt as follows:
COMM PARAMETERS IN EEPROM:
SMODE : STOP
BAUD RATE: 19200
DATA BITS: 8
PARITY: NONE
STOP BITS: 1
ADDR: 0
HARDWARE CONFIGURATION:
COMM CHANNEL: RS485
NOTE
ANALOG OUTPUT: VOLTAGE
GMP343 - VERSION STD 2.0
COPYRIGHT: VAISALA OYJ 2003 -2006
>ZZZZZZZZZZZ
6. Key in the commands with the keyboard of your computer and press enter. In this guide <cr> stands for pressing ENTER .
Responses from the GMP343 are terminated by the following string:
[cr][lf]>
That is a carriage return character, a line feed, and a right angle bracket.
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Operation modes of the GMP343

The GMP343 can operate in three different modes:
- RUN mode
- STOP mode
- POLL mode
In the RUN mode, the GMP343 sends measurement results at regular intervals. The included parameters and the interval can be set by the user. While in the RUN mode, the device will not answer any other command except the S command, which stops the RUN mode and switches the device to STOP mode.
The STOP mode is the default mode of operation for the GMP343, where most of the commands listed in this document are available. You can enter the STOP mode from the RUN mode with the S command, or from the POLL mode with the OPEN<addr> command, where <addr> is the unique address of the GMP343. While in the STOP mode, the GMP343 will respond to all unknown commands with the following string:
Unknown command.[cr][lf]>
The POLL mode is dedicated for bus interfacing. To work in the poll mode, each device must have its own unique address. You can enter the POLL mode by giving the CLOSE command in the STOP mode.
Only a single device can be accessed at a time in the POLL mode. In the POLL mode, you can request a single measumement message from the GMP343 using the SEND<addr> command. While in the POLL mode, the GMP343 will ignore all unknown commands.
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Getting the Measurement Message

Measurement Units

GMP343 outputs the following units:
- Carbon dioxide (ppm)
- Temperature (ºC)
For other measurement units (%, non-metric units), use the Vaisala MI70 indicator.
NOTE
NOTE
The built-in temperature sensor is intended for compensation of the CO2 measurement. By default the compensation is enabled. For more information, see section Temperature, Pressure, Relative Humidity, and
Oxygen Compensations on page 45.
Measurement units (ppm and %) express the CO2 concentration by gas volume.1 % CO2 = 10 000 ppm CO
2

Starting the Continuous Outputting

R <cr>
This command starts the continuous outputting of results (output form defined with the command FORM). Data is printed with the interval defined with the command INTV. Printing can be stopped with the command S.
>r 345.0 ppm
344.1 ppm
343.6 ppm
345.6 ppm
346.1 ppm
344.1 ppm
343.5 ppm
345.5 ppm
>

Stopping the Continuous Outputting

S <cr>
Ends the RUN mode; after this command all other commands can be used.
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Setting the Continuous Outputting Interval

INTV xxxx yyy <cr>
SAVE <cr>
xxxx=output interval (1...1000) default=1 s
yyy=unit (s, min or h)
Example: Output interval is changed to 5 seconds
>intv 5 s INTERVAL : 5 UNIT : S >

Outputting the Reading Once

In STOP mode:
SEND <cr>
In POLL mode:
SEND aa <cr>
aa=address of the transmitter when more than one transmitter is connected to a serial bus (0...99).
The output mode can be changed with the command FORM.
>send
348.7 ppm >

Setting the Serial Interface Measurement Mode

SMODE xxxx <cr>
SAVE <cr>
xxxx= STOP/RUN/POLL
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In STOP mode: Measurements output only by command, all commands can be used (default mode).
In RUN mode: Outputting automatically, only command S can be used.
In POLL mode: Measurements output only with command SEND. For more details on POLL mode, see sectionNetworking Operation on page 37.
The settings are not valid until the device is reset.

Setting Communication Hardware

Communication hardware can be chosen between RS-232 or RS-485. Command parameters are correspondingly 232 and 485.
RSMODE <cr>
SAVE <cr>
The setting is not valid until the device is reset.
>rs mode RSMODE : 232? 485
>save EEPROM saved successfully. >
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Serial Communication Settings

Save the changed settings by entering the SAVE command. The settings are not valid until the device is reset.
SERI <cr>
SAVE <cr>
Baud rate: (300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600,
115200)
Note: When baud rate is > 19200 the character spacing must be > 1 ms. If the character spacing is not in use the device may lose some characters.
Data bits: (7/8)
Parity: (none, even, odd)
Stop bits: (1/2)
Key in the settings after the question mark and press ENTER.
>seri BAUD RATE : 19200 ? 19200 DATA BITS : 8 ? 8 PARITY : NONE ? none STOP BITS : 1 ? 1
>save EEPROM saved successfully. >
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Formatting the Measurement Message

Formatting the Message

This command is used to change the serial output format of the commands
SEND and R.
FORM x <cr>
SAVE <cr>
x= format string
Format string consists of quantities and modifiers. You can select one or more of the following quantities by keying in the abbreviation after
FORM command:
Table 4 Quantities
Abbreviations Quantities
CO2 Filtered CO
CO2RAW Unfiltered CO
CO2RAWUC Unfiltered CO
and corrections (MPC/LC) do not apply. TIME Time passed from last reset ADDR Transmitter address ERR Error flag (0=no error/1=error) in POLL or RUN modes. T Measured temperature P User-set pressure value RH User-set relative humidity value O User-set oxygen value
results. Factory setting.
2
results.
2
results. Compensations (P/T/RH/O2)
2
Table 5 Modifiers
Abbreviations Explations
x.y length modifier (whole numbers and decimal places) #t tabulator #r carriage-return #n line feed "" string constant U5 unit field and length
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Example 1:
>form CO2 " " "ppm" #r#n
>save EEPROM saved successfully. >send
336.3 ppm
Example 2:
>form "Filtered data" CO2 "ppm" #r#n >save EEPROM saved successfully > >send Filtered data 336.9ppm >
Example 3 (both filtered and raw data chosen):
>form CO2 "ppm" " " CO2RAWUC "ppm" #r#n >send
296.5ppm 270.1ppm

Setting Time

TIME x <cr>
SAVE <cr>
x=hh:mm:ss
Time passed since the last power on was displayed. Time always resets to 00:00:00 when power is switched off. However, the user can set the time.
Example (time inquiry):
>time 04:00:52 >
Example (time setting):
>time 12:15:00 12:15:00 >time 12:15:02 > >save EEPROM saved successfully. >
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NOTE
Only approximately 1 % accuracy is obtained with the software clock.

Networking Operation

When several transmitters are connected to the same RS-485 bus it is recommended to use separate power supplies for each transmitter. Make sure that the devices are grounded to the same potential. Otherwise harmful ground currents may be generated or RS-485 common-mode limits may be exceeded.
There is no internal termination for the RS-485 bus on the GMP343. For long RS-485 bus lengths proper termination should be provided externally.

Setting the Transmitter Address

ADDR aa <cr>
SAVE <cr>
aa=address (0...99)
Example (changing address from 0 to 1):
>addr ADDR : 0 ? 1 > >save EEPROM saved successfully. >
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Open and Close

OPEN nn <cr>
nn=address of the transmitter (0...99)
The OPEN command sets the bus temporarily in STOP mode so that the SMODE command can be entered.
CLOSE <cr>
In STOP mode: Command OPEN has no effect, CLOSE sets the transmitter temporarily in POLL mode.
In POLL mode: Command OPEN sets the transmitter temporarily in STOP mode.
Example:
>close
line closed GMP343: 1 line opened for operator commands >send
351.1 ppm
>smode stop SMODE : STOP >

Setting Echoing Mode

ECHO x <cr>
SAVE <cr>
x=ON/OFF (default ON)
In RS-232 mode the device echoes everything back to the user. In RS-485 mode echoing is automatically disabled.
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Preparation for Network Operation

Before GMP343 is connected to the network it must be configured. Normal procedure is shown below:
First connect the device to PC by using RS-232 and when communication is currently open, key in the following commands:
RSMODE 485
ADDR addr
(where addr is 1...99)
SMODE POLL
SAVE
Next turn the power off. Then you can connect the device to RS-485 network.

Commands during Network Operation

When GMP343 is connected to the network, the following commands can be entered:
SEND addr Return latest CO2 value
XP addr pressure Set pressure for compensation XO addr oxygen Set oxygen for compensation XRH addr
humidity
OPEN addr Open device for normal communication (i.e. to
CLOSE Switch the device from STOP-mode to POLL-
Compensation values that are entered with compensation commands (XP, XO, XRH) are used for compensation but they are not stored permanently.
Note that compensation commands do not give any reply. If value in command is not acceptable, the command is rejected.
Set humidity for compensation
STOP-mode)
mode.
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Measurement Range, Data Filtering and Linearization

Setting the Measurement Range

The measurement range of the GMP343 has been set at factory according to the order form. However, you can change the measurement range to optimize measurement performance for a certain concentration level.
To achieve the most accurate 'ppm CO2' measurement, the measurement should be compensated for T, P, %RH, and O environment. The compensation settings are specific to the selected
measurement range, so selecting a suitable measurement range optimizes the compensation performance. Each range also has its own linearization function; see section Linearization on page 45.
There are 6 measurement ranges available. The range always begins with zero and only upper end value is changed.
concentration in the
2
NOTE
RANGE x
SAVE
x = 1...6
Example:
>range 4
1. SPAN (ppm) : 1000.00
2. SPAN (ppm) : 2000.00
3. SPAN (ppm) : 3000.00
4. SPAN (ppm) : 4000.00
5. SPAN (ppm) : 5000.00
6. SPAN (ppm) : 20000.00
RANGE : 4 > >save EEPROM saved successfully.
RANGE-command only optimizes measurement. The scaling of the analog output is an independent issue. Normally it is necessary to change also ALOW and AHIGH values. For more information, see sectionSetting and Testing the Analog Outputs on page 52.
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Measurement Data Filtering

The raw measurement values (measurement interval = 2 seconds) are an input to a chain of three filters: a median, an averaging, and a smoothing filter. The filters can be individually enabled or disabled by setting the filter coefficient to 0 (zero) or by choosing CO2RAW instead of CO2 for
the measurement output quantity (see FORM command).
Figure 8 Entering Measurement Values
Median Filter
Median filter is the first section in the filter chain, removing random peak values caused by external interference. The output of the median filter is the moving median of the values over the set number of measurements. The median filter arranges the values in the order of magnitude and outputs the middle value (not the average) if the number of the measurements is odd. In case an even number is set, the output is the average of the two middlemost measurements.
The lowest reasonable set number of measurements is 3. Note that if the noise distribution is somewhat uniform the median filter does not give any additional value.
The number of the measurements is set by the MEDIAN command. Maximum number of measurements is 13. The default value is 0 (meaning that the median filter is disabled).
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Averaging Filter
The averaging filter calculates a moving average over the user-set period of time. The longer the averaging time is the lower the noise at the measurement signal. For example, if the averaging is set to 30 seconds, the most recent average filter output is the average of the last 15 measurements (2 seconds measurement interval).
The averaging time is set by the AVERAGE command. The default value is 10 seconds, and the maximum filter length is 60 seconds. For longer averaging times, use the smoothing filter instead. Table 6 on page 42 presents the measurement noise as a function of averaging time at 370 ppm CO2:
Table 6 Averaging Times
Averaging Time Noise
0 s ± 3 ppm 10 s ± 2 ppm 30 s ± 1 ppm
Smoothing Filter
The smoothing filter calculates the running average by weighting the most recent measurement by the user-set proportion of the preceding measurement.
By using the smoothing filter, averaging up to even 15 minute periods can be accomplished. The smoothing filter is feasible for the background measurement where fast changes in the CO
common. See the next section to find the difference between smoothing and averaging in regard to response time.
The smoothing factor is set by the SMOOTH command, where the range of the factor is 0 ... 255. The relationship between averaging and smoothing from the noise reducing point of view is like follows:
(SMOOTHING FACTOR × 4) = approx. AVERAGING TIME (s)
The default value is 0 (meaning that the smoothing filter is disabled).
concentration are not
2
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How the Filtering Affects the Response Time
The figure on the next page illustrates the difference of the two filters in regard to time response. The averaging time is set to 40 seconds while the smoothing factor is set to 10 to have about equal noise rejection properties. See also the response time tables presented in SpecificationsResponse time
(90 %) on page 77.
Figure 9 The Difference of the Two Filters in Time Response

Setting the Median Filter

Use the median filter to remove random peak values caused by possible external interference.
MEDIAN x <cr>
SAVE <cr>
x=0...13 (default=0)
>median 3 MEDIAN : 3 >save EEPROM saved successfully (829 ms). >
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Setting the Averaging Filter

Use the averaging filter to reduce the noise of the measurement. Notice the effect on the response time.
AVERAGE x <cr>
SAVE <cr>
x=0...60 seconds (default =10 s)
>average 20 AVERAGING (s) : 20 >save EEPROM saved successfully (829 ms). >

Setting the Smoothing Filter

Use the smoothing filter to reduce the noise of the measurement for long averaging periods. Notice the effect on the response time.
SMOOTH x <cr>
SAVE <cr>
x=0...255 (default =0)
>smooth 10 SMOOTH : 10 >save EEPROM saved successfully (829 ms). >

Flushing the Filters (Resynchronization)

With this command you can flush the filters to get rid of the effect of the past measurements. This feature is useful if long filtering lengths are used.
RESYNC <cr>
>resync >
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Linearization

Due to the principle of the CO2 absorption, the sensor of GMP343 produces a signal which is not linear in relation to the CO2 concentration. However, the output signal is linearized with the internal linearization
function. The user can disable the internal linearization function to achieve a signal proportional to the absorption.

Setting the Linearization ON/OFF

LINEAR x <cr>
SAVE <cr>
x=ON or OFF (default=ON)
Example:
>linear LINEAR : ON ? > >save EEPROM saved successfully.
>

Temperature, Pressure, Relative Humidity, and Oxygen Compensations

The measurement result of an NDIR CO2 sensor such as the GMP343 is proportional to the absolute number of CO of the sensor. Hence, according to the ideal gas law, the 'ppm CO is pressure and temperature dependent. Additionally, background gases
such as humidity and oxygen have an effect on the absorption strength of CO
.
2
The factory calibration of GMP343 is carried out using dry N2 and CO2 mixtures. In other words, the relative humidity and the oxygen
concentration of the calibration gases are 0 %.
molecules in the active volume
2
' output
2
To achieve the most accurate 'ppm CO2' measurement, the measurement should be compensated for T, P, % RH, and O2 concentration in the environment. In GMP343 these compensations are a built-in option. The
compensated output corresponds to 'ppm CO2' in the actual environment
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(T, P, RH, and O2). The temperature, pressure, relative humidity, and oxygen compensations are enabled as a factory default (default
environmental parameters: pressure 1013 hPa, relative humidity 50 % RH, oxygen 20.95 % O2). The compensation settings are specific to the selected
measurement range, so selecting a suitable measurement range also optimizes the compensation performance.
The compensation algorithm of GMP343 eliminates the dependences of the CO2 measurement, whether they are related to the physics of the
measurement or the instrument itself. The temperature compensation of GMP343 is based on built-in temperature sensor while the values of the other environmental parameters should be changed by the user, if they vary from the default.
Note, that from the measurement accuracy point of view, the effect of humidity and oxygen is less significant compared to the effect of temperature and pressure.
Without compensation, the effect of oxygen on the CO2 reading is approximately - 0.09 % of reading / % O2. In most circumstances, the oxygen concentration does not vary from the default, so normally there is
no need to change the oxygen concentration settings.
Without compensation, the effect of humidity on the CO2 reading is
approximately 0.05 % of reading / g/m3 H2O. Since relative humidity is strongly dependent on temperature, the humidity dependence is in terms of
absolute humidity, g/m3 H2O.
Compensation of each environmental parameter can be disabled/enabled individually by setting the corresponding software parameter 'OFF' or 'ON', or by choosing CO2RAWUC for the measurement quantity (see FORM command).
The internal compensation of GMP343 is the most accurate way to compensate for changing environmental parameters. However, if more information is needed on different compensations, please contact your Vaisala representative.
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Temperature Compensation ON/OFF

The internal temperature sensor is located in the measurement chamber. Temperature compensation is done automatically unless for some reason you want to take the compensation feature off.
To enable or disable temperature compensation, use the commands:
TC x <cr>
SAVE <cr>
x=ON/OFF (default =ON)
>tc on TC : ON >tc off TC : OFF > >save EEPROM saved successfully. >

Setting the Oxygen Concentration

To set the oxygen concentration value, use the commands:
O x <cr>
SAVE <cr>
x=0...100 % (default =20.95 %)
>o 21 OXYGEN (%): 21.00 >save EEPROM saved successfully. >
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Setting Oxygen When the Device Is in POLL-mode
To set oxygen value in POLL-mode, use the following addressable command:
XO addr x <cr>
The device does not reply to the command. If given oxygen value is not within limits, the command is rejected. The given value is written to volatile memory, where it will be overwritten either by next XO-command or O-command. At start the first compensation value is a value given by O-command if it was saved by SAVE-command. Purpose of the XO­command is continuous update of compensation value sent by another measurement device.

Oxygen Compensation Mode

To enable or disable the oxygen compensation, use the commands:
NOTE
OC x <cr>
SAVE <cr>
x=ON/OFF (default =ON)
Check that the ambient pressure value is correct. The correct pressure value is needed for oxygen compensation even if the pressure compensation is disabled.
>oc on OC: ON > >save EEPROM saved successfully. >
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Setting the Ambient Pressure (hPa)

The pressure value is needed in pressure, humidity, and oxygen compensations. To set the ambient pressure value, use the commands:
P x <cr>
SAVE <cr>
x=700...1300 hPa (default =1013 hPa)
Sets ambient pressure (hPa) to be used in compensation calculations.
>p 1100 PRESSURE (hPa)): 1100.000 >p PRESSURE (hPa) : 1100.000 ? > >save EEPROM saved successfully. >
Setting Pressure When the Device Is in POLL-mode
To set pressure value in POLL-mode, use the following addressable command:
XP addr x <cr>
The device does not reply to the command. If given pressure value is not within limits, the command is rejected. The given value is written to volatile memory, where it will be overwritten either by next XP-command or P-command. At start the first compensation value is a value given by P- command if it was saved by SAVE-command. Purpose of the XP- command is continuous update of compensation value sent by another measurement device.
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Pressure Compensation ON/OFF

To enable or disable the pressure compensation, use the commands:
PC x <cr>
SAVE <cr>
x=ON/OFF (default =ON)
>pc off PC: OFF >pc on PC : ON ? >save EEPROM saved successfully. >

Setting Ambient Relative Humidity

To set the ambient relative humidity value, use the commands:
RH x <cr>
SAVE <cr>
x=0 ... 100 % RH (default =50 %)
>rh HUMIDITY (%RH): 0.00 ? 24 >save EEPROM saved successfully. >
Setting Humidity When the Device Is in POLL-mode
To set relative humidity value in POLL-mode, use the following addressable command:
XRH addr x <cr>
The device does not reply to the command. If given humidity value is not within limits, the command is rejected. The given value is written to volatile memory, where it will be overwritten either by next XRH- command or RH-command. At start the first compensation value is a value given by RH-command if it was saved by SAVE-command. Purpose of the XRH-command is continuous update of compensation value sent by another measurement device.
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Relative Humidity Compensation ON/OFF

To enable or disable the humidity compensation, use the commands:
RHC x <cr>
SAVE <cr>
x=ON/OFF (default =ON)
NOTE
Check that the ambient pressure value is correct. The correct pressure value is needed for RH compensation even if the pressure compensation is disabled.
>rhc on RHC : ON >rhc off RHC : OFF > >save EEPROM saved successfully. >
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Setting and Testing the Analog Outputs

GMP343 has one analog output channel. The channel outputs either current or voltage signal according to the order configuration. The analog output always gives the filtered CO2 results regardless of the quantity set
with FORM command.

Analog Output Hardware

AMODE <cr>
SAVE <cr>
Analog output hardware can be chosen between current or voltage output. Command parameters are correspondingly I (for current) and U (for voltage).
>amode AMODE : I ? U > >save EEPROM saved successfully. >
You can scale the chosen analog output signal as follows:
- When you have current output, you can set any value between 0 ... 4 mA for the current signal low level. The default value is 4 mA (command ILOW). The high value is always 20 mA.
- When you have voltage output, you can set any value between 0 ... 5 for the voltage signal high level (command UHIGH). The low value is always 0 V.
Remember to set the analog output error value within the range of current/ voltage output. See the command AERR.
The concentration range of the analog output, corresponding to the signal range set above, can be chosen by determining the low and high values for the measurement range (AHIGH, ALOW).
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Setting the Limit of the Current Output Range

You can expand the current output range for example 4...20 mA to 0...20 mA. The range available is 0...4 mA.
ILOW <cr>
SAVE <cr>
Key in the low current value (mA) and press ENTER.
>ilow ILOW (mA) : 4.000 ? 0 >save EEPROM saved successfully. >

Setting the High Limit of the Voltage Output Range

You can set the hight voltage value: 0...5 V.
UHIGH <cr>
SAVE <cr>
Key in the high voltage value (V) and press ENTER.
>uhigh UHIGH (V) : 5.000 ? 1 > >save EEPROM saved successfully. >
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Setting the High Limit of the Concentration Range

Sets the hight CO2 concentration value, which corresponds to the analog output high value.
AHIGH <cr>
SAVE <cr>
Key in the highest concentration value (ppm) and press ENTER.
>ahigh AHIGH (ppm) : 1000.0 ? 1200 > >save EEPROM saved successfully. >

Setting the Low Limit of the Concentration Range

Sets the low CO2 concentration value, which corresponds to the analog output low value.
ALOW <cr>
SAVE <cr>
Key in the lowest concentration value (ppm) and press ENTER.
>alow ALOW (ppm) : 0.0 ? 20 > >save EEPROM saved successfully. >
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Setting the Analog Output Overrange Clip

This command clips the analog output signal at the high value when the signal goes over range. In case of the current output the current will not go higher than 20 mA or below the low value current (set with ILOW). The voltage output will not go higher than the voltage set with UHIGH.
ACUT x <cr>
SAVE <cr>
x=ON/OFF
>acut ACUT : OFF ? ON >acut ACUT : ON ? OFF > >save EEPROM saved successfully. >

Testing the Analog Output

When you want to test the operation of the analog output use this command to force the output to the set value. The value in the analog output can then be measured with a current/voltage meter. The set value remains valid until you give the ATEST command without a value or RESET the transmitter.
ATEST <cr>
x=the given test value (mA or V)
>atest 1 Test voltage set at 1 V. Use command without any parameters to stop test mode. >atest Voltage test mode stopped.
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Setting the Analog Output Error Level

Factory default states for analog outputs during error condition are the maximum values of the measuring range=2.5 V / 5 V / 20 mA.
AERR x <cr>
SAVE <cr>
x=error value (mA) or (V)
Acceptable ranges: 0...20 mA, 0...6 V
Example:
>aerr AERR (V) : 5.000 ? 0 > >save EEPROM saved successfully. >
NOTE
The error output value must be within a valid range for current (0...20 mA) or voltage output (0...6 V) regardless of the UHIGH setting.
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Device Information and Other General Commands

Device Information List

This command outputs the information about the device.
? <cr>
This command outputs the information about the device even in POLL­mode.
?? <cr>
>?? GMP343 / 2P0.33 SNUM : Y3040008 CALIBRATION : 2007-04-20 CAL. INFO : Vaisala Oyj SPAN (ppm) : 4000 PRESSURE (hPa) : 1013.000 HUMIDITY (%RH) : 50.00 OXYGEN (%) : 20.95 PC : ON RHC : OFF TC : ON OC : OFF ADDR : 0 ECHO : ON SERI : 19200 8 NONE 1 SMODE : STOP INTV : 1 S

Show the Output Quantities

Lists the parameter abbreviations to be used in FORM command.
CALCS <cr>
>calcs CO2 - Filtered CO2 CO2RAW - Raw CO2 CO2RAWUC - Uncompensated raw CO2 TIME - Time since last reset ADDR - Device address ERR - Error flag T - Gas temperature P - User-set pressure value RH - User-set relative humidity value O - User-set oxygen value
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Linear and Multipoint Corrections

Shows the last linear and multipoint correction values.
CORR <cr>
>corr LC : OFF
Linear correction Reading Reference
0.00 0.000
1000.00 1000.000
MPC : OFF
Multipoint correction Reading Reference
0.00 0.000
1000.00 1000.000
>

Error Messages

The ERRS command shows the error messages received. For a list of possible errors, refer to Table 7 on page 72.
ERRS <cr>
>errs No errors detected. >errs ERROR E02: IR source failure. ERROR E06: Temperature measurement failure (recovered 1 h 9 min ago). WARNING W01: Watchdog reset. >
The ERRS R command resets the error states.
ERRS R <cr>
>errs r
OK: No errors detected. Error states cleared.
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Command List

This command displays a list of all the commands.
HELP <cr>

Showing the Parameters

PARAM <cr>
>param RSMODE : 232 ADDR : 0 SERI : 19200 8 NONE 1 SMODE : STOP FORM : CO2 \r \n INTV : 1 S ECHO : ON
AMODE : U ACUT : ON AERR (V) : 2.50 AHIGH (ppm) : 3000.00 ALOW (ppm) : 0.00 ILOW (mA) : 4.00 UHIGH (V) : 2.50
RANGE : 4 MEDIAN : 0 AVERAGE (s) : 30 SMOOTH : 0 LINEAR : ON LC : OFF MPC : OFF HEAT : OFF
OXYGEN (%) : 20.95 PRESSURE (hPa) : 1013.000 HUMIDITY (%RH) : 50.00 OC : OFF PC : ON RHC : OFF TC : ON

Software Version Information

VERS <cr>
>vers GMP343 / 2P0.33 >
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Memory Handling

Reverting the Factory Parameters

Use this command to revert the original factory settings.
>factory Parameters loaded from Flash. >
Remember to check the settings after using this command.

Saving the Setting

SAVE <cr>
Saves the parameters and settings to EEPROM memory.

Setting the Optics Heating ON/OFF

Enables or disables optics heating.
HEAT <cr>
x=ON or OFF (default =ON)
Example:
>heat HEAT : ON ? off >

Resetting the Transmitter

RESET <cr>
This command resets the device. If the device is in RUN mode, outputting the results starts immediately after resetting.
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CHAPTER 5
CALIBRATION AND ADJUSTMENT
This chapter contains information for performing the calibration and adjustment of the GMP343.
In this user's guide the term calibration means comparing the transmitter's reading to a reference concentration. Adjustment, which is usually done after calibration, the reading of the transmitter is changed to correspond to the reference concentration. After adjustment, the original calibration certificate shipped with the product is not valid anymore.
The GMP343 can be sent to Vaisala for calibration, or be calibrated by the user.

Calibration Interval

GMP343 is calibrated as shipped from the factory. The recommended calibration interval is one year. The operating conditions affect the long­term stability. For more information, see sections Operating Conditions on
page 79 and Performance on page 75 (long-term stability). In a harsh
operating environment it is recommended to check readings more often than in an easy environment.

Factory Calibration and Adjustment

You can send the device to Vaisala Service Center for calibration and adjustment. For more information, see Product Returns on page 73.
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Calibration and Adjustment by the User

Calibration and adjustment are carried out by using the serial communications and the calibration gas(es).
Additional equipment needed:
- power supply 11...36 VDC
- PC and PC connection cable (Vaisala order code 213379) with optional USB adapter (Vaisala order code 219686)
- calibration gases and tubing
- calibration adapter is required for calibrating the diffusion model (Vaisala order code GMP343ADAPTER)
- pressure regulator and flow meter
- barometer (for measuring ambient pressure)

Calibration (Checking)

The gas concentration of the reference gases must cover the measurement range of the device.
Checking the Compensations
1. Connect GMP343 to a PC and open the terminal program. For more information, see section Connecting GMP343 to PC on page 27.
2. Connect the 24 VDC supply power to GMP343.
3. Compensations must always be enabled during the calibration procedure. Use the ? command to verify the status of the compensations for ambient pressure, temperature, relative humidity, and oxygen concentration:
?<cr>
4. If all compensations are not enabled, make note of the current settings so that you can restore them after the calibration if desired. Then issue the following commands to enable the compensations:
PC ON<cr>
TC ON<cr>
RHC ON<cr>
OC ON<cr>
5. You must also set the ambient pressure, relative humidity, and oxygen concentration values of the calibration gas correctly. Typically the relative humidity of the calibration gases is 0 % RH. Oxygen
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concentration of nitrogen mixture gases is usually 0 %. If necessary, adjust the values. For example:
P 1000.3<cr>
RH 0<cr>
O 0<cr>
For more information on compensations, see section Temperature,
Pressure, Relative Humidity, and Oxygen Compensations on page 45.
Measurements in Reference Gases
1. If your GMP343 is the diffusion model, remove the filter cover and place the calibration adapter onto the probe.
2. Let the device warm up for 30 minutes to achieve full calibration accuracy.
3. Turn on the calibration mode by giving the command CALIB ON. This changes some of the transmitter parameters for the duration of the calibration.
CALIB ON <cr>
4. Connect the reference gas to the inlet of GMP343 transmitter and let the gas flow for 5 minutes (about 0.5 l / min).
5. To output the measurement result, key in the command R. Check that the reading is stabilized and write down the CO2 reading (ppm). Enter
command S to stop outputting. For the best calibration result, it is recommended to calculate an average of 20 measurements instead of a single reading.
6. Shut off the reference gas flow and remove the tubings from the gas bottle. When calibrating at several points, connect the other gases to GMP343 similar to the first gas and carry out the measurements as instructed above (steps 6 and 7).
7. After measurements turn off the calibration mode by giving the command CALIB OFF (this reverts to the original transmitter settings).
CALIB OFF <cr>
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Adjustment in 1...2 Points

First carry out checking the compensations and perform the reference gas measurements as instructed in the previous section, Calibration and
Adjustment by the User on page 62. Then continue as follows:
1. Key in the command
LCI <cr>
2. Key in the reading at the reference gas (ppm) and press ENTER (1.Reading?).
3. Key in the reference gas concentration (ppm) and press ENTER (Reference?).
4. When making a one-point calibration press ENTER again and go to step 6 in this list. When making a two-point calibration, key in the reading at the second reference gas and press ENTER (2.Reading?).
5. Key in the reference gas 2 concentration (ppm) and press ENTER (Reference?).
6. Now the correction values are calculated, but the adjustment is not valid until the correction is confirmed.
7. Confirm the new correction values with the command
LC ON <cr>
8. Use the command R to check with both reference gases that the correction has taken place and the readings are ok.
9. Save the settings:
SAVE <cr>
Saves parameters and settings to EEPROM memory.
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Chapter 5 __________________________________________________ Calibration and Adjustment

Adjustment in 3...8 Points

First carry out checking the compensations and perform the reference gas measurements as instructed in the previous section, Calibration and
Adjustment by the User on page 62. Then continue as follows:
1. Feed the readings (Reading?) and the corresponding concentrations (Reference?) with the command
MPCI <cr>
2. Confirm the adjustment and the new correction values with the command
MPC ON <cr>
3. Save the settings with the command
SAVE <cr>
Saves parameters and settings to EEPROM-memory.
NOTE
Example of the 2-Point Adjustment Procedure
The following section presents an example of the 2-point adjustment procedure with reference gas concentrations of 0 ppm and 1007 ppm.
Use the actual concentrations given usually in the side of the gas bottle. For example, a gas with a nominal 1000 ppm CO2 concentration might actually contain 1007 ppm CO2.
1. First turn on the calibration mode for measuring reference gases.
> >calib on Calibration mode started. Use CALIB OFF to stop the mode.
2. The GMP is now measuring the first reference gas (0 ppm). Use command R and let the reading stabilize for several minutes. Calculate the average reading (reading 1).
>r ...28.2
28.2
28.1
28.1
28.2
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3. The GMP343 is now measuring the second reference gas (1007 ppm). Use command R and let the reading stabilize for several minutes. Calculate the average reading (reading 2).
> >r
1067.1
1066.8
1067.2
1066.7
1066.6
4. Turn off the calibration mode with command CALIB OFF.
>calib off Calibration mode stopped.
5. Next feed the readings: use command LCI to feed the first and second reference gas readings (28 ppm and 1066 ppm), and the corrected values (= the concentrations of the reference gases, 0 ppm and 1007 ppm).
>lci Reading Reference
0.00 0.000
1000.00 1000.000 NOTE: Entering new correction values all previous correction points! Abort without losing correction points by using ESC.
1. Reading ? 28
Reference ? 0
2. Reading? 1066
Reference? 1007
6. Confirm the adjustment with command LC ON.
>lc LC : OFF ? on
7. Check the reading with the second reference gas, 1007 ppm.
>r
1005.4
1006.2
1007.1
1007.1
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Chapter 5 __________________________________________________ Calibration and Adjustment
8. Check the reading with the first reference gas, 0 ppm.
>r
0.2
0.1
-0.1
-0.1
-0.0
-0.2
9. Save the settings.
save> EEPROM saved successfully.
>
NOTE
You can revert the GMP343 back to factory settings with the command FACTORY.
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Chapter 6 ______________________________________________________________ Maintenance
CHAPTER 6
MAINTENANCE
This chapter instructs in the basic maintenance of the GMP343.

Cleaning the Probe Housing

You can clean the probe housing wiping with a moist cloth. Note the following precautions when cleaning:
- Do not immerse the GMP343 in liquid to clean it.
- Do not attempt to clean the optical surfaces except as described in section Changing the Filter and Cleaning the Optics (Diffusion Model
Only) on page 70. The optical surfaces of the flow-through model
should only be cleaned by a Vaisala service center.
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Changing the Filter and Cleaning the Optics (Diffusion Model Only)

The optics of the diffusion model are well protected by the filter, and it can tolerate some dirt on the optics as the measurement is compensated for the reduction of signal. For this reason, there is typically no reason to perform any cleaning actions even if the probe appears slightly dirty on the outside.
If the filter is very contaminated, or if the probe gives the error code E07 Measurement signal level too low, follow the procedure below to change the filter, and if necessary, clean the optical surfaces. A new standard diffusion filter and filter cover can be ordered from Vaisala (order code GMP343FILTER).
CAUTION
NOTE
Do not clean the optical surfaces in any other manner. If further cleaning is required to restore error-free measurement, contact Vaisala Service.
Handle the diffusion filter carefully to prevent contaminants or mechanical stress from damaging the filtering surface.
1. Rotate and remove the filter cover.
2. Take a firm hold on the frame of the diffusion filter, and pull it out. Note that the threads for the filter cover are sharp.
Figure 10 Opening the Diffusion Filter
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Chapter 6 ______________________________________________________________ Maintenance
3. Blow on the mirror and window area with clean instrument air to remove any loose particles.
CAUTION
0704-021
Figure 11 Optics
The following numbers refer to Figure 11 on page 71: 1=Mirror 2 = Window
4. If the mirror and/or window seem dirty, perform the following steps:
Do not rub or wipe the optical surfaces, as that may scratch or otherwise damage them.
a. Pour some pure ethanol or isopropyl alcohol on the window and
swish it around to clean the dirt. Pour out the liquid when done.
b. Clean the mirror in the same manner.
c. Let the surfaces dry before continuing with the next step.
5. Replace the diffusion filter. Push the end of the filter gently to snap it into place.
6. Replace the filter cover.
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Error States

In case of an error function the outputs are as follows:
- Serial line: In STOP mode the error code and description (see the Table 6 below) is shown when keying in the command: ERRS. In POLL or RUN mode the error flag is set to 1 (if the error flag is included in the message format, see FORM-command). Reset the error state with a command ERRS R.
- Analog output shows the error level (can be set by using the AERR­command. Factory setting: 5 V or 20 mA).
Table 7 Troubleshooting Errors
Error code Error description Interpretation Action
E01 EEPROM checksum failure Internal transmitter failure Return the device to
Vaisala Service
E02 IR source failure Internal transmitter failure Return the device to
Vaisala Service.
E03 FPI failure Internal transmitter failure Return the device to
Vaisala Service.
E04, E05 Heater failure Internal transmitter failure Return the device to
Vaisala Service.
E06 Temperature measurement
failure
E07 Measurement signal level
too low
W01 Watchdog reset occured Software defect In case this warning
W02 Stack overflow Software defect In case this warning
Operation temperature is out of allowed range. Analog output: Error level is shown if temperature compensation is enabled. Otherwise, output is normal.
Measurement chamber is contamined or the lamp is degraded.
Ensure that the operating temperature is -45...+85 °C (-49...185 °F). In case of constant error, return the device to Vaisala Service.
Change the filter and clean the optics according to the instructions in section
Changing the Filter and Cleaning the Optics (Diffusion Model Only) on page 70. In case of
constant error, return the device to Vaisala Service.
appears frequently, return the device to Vaisala Service.
appears frequently, return the device to Vaisala Service.
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Chapter 6 ______________________________________________________________ Maintenance
In all error cases first check that the probe is connected properly, then reset the transmitter by disconnecting it. In case of constant error, please contact Vaisala technical support. See section Technical Support on page 73.
CAUTION
Please note that there are no user-serviceable parts inside the GMP343 transmitter body. The back flange shall not be opened except by authorized Vaisala service personnel.

Technical Support

For technical questions, contact the Vaisala technical support by e-mail at
helpdesk@vaisala.com. Provide at least the following supporting
information:
- Name and model of the product in question.
- Serial number of the product.
- Name and location of the installation site.
- Name and contact information of a technically competent person who can provide further information on the problem.

Product Returns

If the product must be returned for service, see www.vaisala.com/returns.
For contact information of Vaisala Service Centers, see
www.vaisala.com/servicecenters.
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Chapter 7 ____________________________________________________________ Technical Data
CHAPTER 7
TECHNICAL DATA
This chapter provides the technical data of the GMP343.

Performance

Sensor
Vaisala CARBOCAP
®
Measuring principle Single-Beam Dual-Wavelength NDIR
Measurement range options 0 ... 1000 ppm
0 ... 2000 ppm 0 ... 3000 ppm 0 ... 4000 ppm 0 ... 5000 ppm 0 ... 2 %
Accuracy (excluding noise) at 25 °C and 1013 hPa after factory calibration with 0.5 % accurate gases with different range options
0 ... 1000 ppm 0 ... 2000 ppm - 0 ... 2 %*
* Accuracy below 200 ppm CO
Noise (repeatability) at 370 ppm CO
2
2
with no output averaging with 30 s output averaging
Short-term stability (up to 6 hours) at 370 ppm CO
±(3 ppm CO ±(5 ppm CO
not specified for the 2 % range option
±3 ppm CO ±1 ppm CO
±1 ppm CO
2
+ 1 % of reading)
2
+ 2 % of reading)
2
2
2
2
Long-term stability
In easy operating conditions In moderate oper. conditions In harsh operating conditions
* Always at least ±10 ppm CO
2
±2 % of reading */ year ±2 % of reading */ 6 months ±2 % of reading */ 3 months
See Figure 12 on page 79.
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Effects of Temperature, Pressure, Relative Humidity, and Oxygen

The temperature compensation of GMP343 is based on the built-in Pt1000 temperature sensor. The values of pressure, relative humidity, and oxygen must be input by the user, if they vary from the default.

Temperature

Table 8 Effect of Temperature on Accuracy with Temperature
Compensation
CO2 range options 0 ... 1000 ppm 0 ... 2000 - 5000 ppm 0 ... 2 %
Temperature °C (°F) Accuracy (% of reading)* +10 ... +40 (+50 ... +104)
+40 ... +60 (+104 ... +140)
-40 ... +10 (-40 ... +50)
±1 ±2 ±3
±1 ±3 ±3
±2 ±4 ±5
NOTE
* Always at least ±10 ppm CO2.
Temperature compensation is performed by an integrated Pt1000 element.
The specifications in the table above are valid when temperature change is < 1 °C / min. If optics heating is in use, the > 500 ppm accuracy values should be multiplied by a factor of 2.
Effect on accuracy without compensation (typ.): -0.35 % of reading / °C

Pressure

Integrated pressure sensor is not included in GMP343.
Table 9 Effect of Pressure on Accuracy with Pressure
Compensation
CO2 range option 0 ... 1000 ppm 0 ... 2000 ppm - 2 %
Pressure (hPa) Accuracy (% of reading) 900 ... 1050
700 ... 1300
±0.5 ±1
±1 ±2
Effect on accuracy without compensation (typ.): +0.15 % of reading /hPa
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Chapter 7 ____________________________________________________________ Technical Data

Humidity

Effect on accuracy with humidity compensation:
±0.006 % of reading / g/m3 H2O below 1000 ppm CO
±0.02 % of reading / g/m3 H2O above 1000 ppm CO
2
2
The values above only apply in normal ambient pressure. Effect on accuracy without humidity compensation (typ.):
+0.05 % of reading / g/m3 H2O
For more information on operating humidity range, see Figure 12 on page
79.

Oxygen

Effect on accuracy with oxygen compensation at 20.9 %O2:
±0.2 % of reading
Effect on accuracy without oxygen compensation (typ.):
-0.09 % of reading / %O
2

Response time (90 %)

Table 10 Diffusion Model
Filter attached Averaging (s) Response (s)
Yes 0 75 Yes 10 80 Yes 30 82 No 0 <2 No 10 12 No 30 30
Table 11 Flow-through Model
Gas flow (l/min) Averaging (s) Response (s)
0.3 0 26
0.3 10 34
0.3 30 44
1.2 0 8
1.2 10 15
1.2 30 23
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Flow dependence of flow-through model 0.3 % of reading / 1 / min
Warm-up time
full accuracy ±0.5 % full accuracy
10 min 30 min

Inputs and Outputs

Operation voltage 11 ... 36 VDC
Power consumption
without optics heating <1 W
with optics heating <3.5 W
Analog outputs
Current output range
resolution max load
Voltage output range
resolution min. load
4 ... 20 mA 14 bits 800 @ 24 VDC 150 @ 10 VDC
0 ... 2.5 V, 0 ... 5 V 14 bits (13 bits with 0...2.5 V) 5 k
Temperature dependence of the analog outputs ±0.005 % of reading / °C
Digital outputs RS-485 (two-wire)
RS-232
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Chapter 7 ____________________________________________________________ Technical Data
020
90
70
80
100
60
50
40
10
30 40 50 60-40 -30 -20 -10
30
20
10
0
%RH
Temperature (°C)
Easy Moderate Harsh Stability not specified

Operating Conditions

The GMP343 operating conditions in terms of temperature (T) and relative humidity (RH) are illustrated in the following graph:
0704-024-B
Figure 12 GMP343 Operating Conditions
Temperature operating
storage
-40 ... +60 °C (-40 ... +140 °F)
-40 ... +70 °C (-40 ... +158 °F)
Humidity See Figure 12 on page 79.
Pressure compensated range 700 ... 1300 hPa
operating <5 bar
Oxygen 0 ... 100 %O
2
Gas flow rate for flow-through model 0 ... 10 liters / min
Internal volume of the measurement chamber of flow­through model 59 ml ±1 ml
Electromagnetic compatibility EN61326-1, Generic Environment
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Materials

Housing Anodized aluminium
Filter cover PC
IP classification
Housing (cable attached) Diffusion filter (weather protection) Diffusion filter (sintered PTFE)
IP67 IP65 IP66
Cable connector type 8-pin M12
Weight (probe only) 360 g

Spare Parts and Accessories

Table 12 List of Spare Parts and Accessories
Description Order code
Wall mounting bracket GMP343BRACKET Mounting flange GMP343FLANGE Standard diffusion filter (weather protection, IP65) + filter cover GMP343FILTER Diffusion filter (sintered PTFE filter, IP66) + filter cover 215521 Calibration adapter (for the diffusion model) GMP343ADAPTER Junction box JUNCTIONBOX-8 Probe cable with M12 female connector, 2 m GMP343Z200SP Probe cable with M12 female connector, 6 m GMP343Z600SP Probe cable with M12 female connector, 10 m GMP343Z1000SP PC connection cable, 2 m 213379 USB adapter (USB-D9 serial connection cable) 219686 Interface cable for MI70, 2 m DRW216050SP Soil adapter kit for horizontal positioning (includes sintered PTFE filter) 215519 Soil adapter kit for vertical positioning (includes sintered PTFE filter) 215520
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Appendix A ______________________________________________________________ Dimensions
APPENDIX A
DIMENSIONS
This appendix contains the dimension drawings for the GMP343.
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User’s Guide ______________________________________________________________________
45
1.77
55
2.17
42
49.0
881
4.7
571
88.6

GMP343 (Flow-through)

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Appendix A ______________________________________________________________ Dimensions
55
2.17
52.5
2.07
491
46.7
181
31.7

GMP343 (Diffusion)

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Calibration Cap

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Appendix A ______________________________________________________________ Dimensions

Mounting Flange

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User’s Guide ______________________________________________________________________

Junction Box

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Appendix A ______________________________________________________________ Dimensions

Mounting Bracket

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User’s Guide ______________________________________________________________________
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Appendix B ________________________________________________________ List of Commands
APPENDIX B
LIST OF COMMANDS
This appendix lists the serial commands of the GMP343.

Measurement Commands

The bold text in the brackets is a default setting. Key in the commands with the keyboard of your computer and press enter. In this guide, <cr> stands for pressing ENTER.
R Start the continuous output
S Stop the continuous output
ECHO Turn the serial interface echo ON/OFF
INTV Set the continuous output interval
SEND Output the reading once
SMODE Set the serial interface
SERI Serial line settings (default 19200 8 NONE) baud: 300 ... 115200
ADDR Set the device address
CLOSE Close the line to POLL mode
OPEN Open temporarily connection to the POLL-mode device
FORM Set the output format of SEND and R commands
RSMODE Set the output hardware to use either RS-232 or RS-485
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Filtering Commands

AV E R A G E Set the averaging filter
SMOOTH Set the smoothing filter
MEDIAN Set the median filter
RESYNC Flush (clear) all the filters

P, T and RH Compensation Commands

P Set local pressure (hPa) for compensation
PC Pressure compensation mode
RH Set local humidity (% RH) for compensation
RHC Humidity compensation mode
TC Temperature compensation mode
O Set the oxygen for compensation
OC Oxygen compensation mode
XP Set local pressure (hPa) for compensation (POLL-mode)
XO Set oxygen for compensation (POLL-mode)
XRH Set local humidity (% RH) for compensation (POLL-mode)

Device Handling Commands

RESET Reset device
FACTO RY Revert the factory parameters
SAVE Save parameters to EEPROM

Device Information Display Commands

? Output the information about the device
?? Output the information about the device in POLL-state
CALCS Display measured parameters
CORR Display linear and multipoint corrections
ERRS List the error messages
HELP List the commands on the current level
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Appendix B ________________________________________________________ List of Commands
PARAM Display parameters
TIME Display or set time since reboot
VERS Display the SW version information

Calibration Commands

CALIB ON Turn on the calibration mode
CALIB OFF Turn off the calibration mode
LC Linear correction mode
LCI Enter linear correction
MPC Multipoint correction mode
MPCI Enter multipoint correction

Setting and Testing the Analog Outputs

AMODE Set analog output HW (current or voltage mode)
AHIGH Analog output high concentration value
ALOW Analog output low concentration value
ACUT Analog output over range cut
ILOW Analog output low current value
UHIGH Analog output high voltage value
AERR Change the analog error output value
ATEST Test the analog outputs

Advanced Measurement Commands

LINEAR Set linearization ON/OFF
HEAT Set optics heating ON/OFF
RANGE Set measurement range to optimize performance
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www.vaisala.com
*M210514EN*
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