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USER'S GUIDE
Vaisala CARBOCAP® Carbon Dioxide
Calibrator for the GMP220 series probes
GM K220
U421EN-1.1
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PUBLISHED BY
Vaisala Oyj Phone (int.): +358 9 8949 1
P.O. Box 26 Fax: +358 9 8949 2227
FIN-00421 Helsinki
Finland
Visit our Internet pages at http://www.vaisala.com/
© Vaisala 2006
No part of this manual may be reproduced in any form or by any means, electronic or
mechanical (including photocopying), nor may its contents be communicated to a third
party without prior written permission of the copyright holder.
The contents are subject to change without prior notice.
Please observe that this manual does not create any legally binding obligations for
Vaisala towards the customer or end user. All legally binding commitments and
agreements are included exclusively in the applicable supply contract or Conditions of
Sale.
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______________________________________________________________________________________
Table of Contents
CHAPTER 1
GENERAL INFORMATION...................................................................... 2
Safety.................................................................................. 2
Warranty............................................................................. 2
CHAPTER 2
PRODUCT DESCRIPTION...................................................................... 3
Introduction ........................................................................ 3
GMK220 Calibrator for the GMP220 Series Probes ............. 4
Additional equipment ......................................................... 5
CHAPTER 3
OPERATION........................................................................................... 6
Spot checking..................................................................... 6
Two-point calibration .......................................................... 9
CHAPTER 4
TECHNICAL DATA ................................................................................13
VAISALA _____________________________________________________________________________1
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User's Guide __________________________________________________________________________
CHAPTER 1
GENERAL INFORMATION
Safety
Throughout the manual, important safety considerations are
highlighted as follows:
WARNING
CAUTION
NOTE
Warranty
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.
Vaisala issues a guarantee for the material and workmanship of this
product under normal operating conditions for one year from the date
of delivery. Exceptional operating conditions, damage due to careless
handling or misapplication will void the guarantee.
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Chapter 2______________________________________________________________Product description
CHAPTER 2
PRODUCT DESCRIPTION
Introduction
Although Vaisala's CO2 instruments are inherently stable, periodical
checkings should be performed according to the recommendations
given in the relevant user's guide. The GMK220 calibrator (Figure 1)
is intended for spot checking and two-point calibration of the carbon
dioxide probes GMP221 and GMP222, which currently are used in
Vaisala's GMT220 and GMM220 series CO2 transmitters.
NOTE
GMK220 can be used for
• spot checking with one reference gas
• two-point calibration with two reference gases
Spot checking can be carried out when there is a need to check if the
probe is operating correctly. If adjustement is needed, two-point
calibration shall be carried out.
GMK220 needs only the probes
For checking and calibration, the GMK220 needs only the probes, not
the whole transmitter. The GMK220 calibrator calibrates and stores
the calibration parameters to the non-volatile memory in the probes.
This enables true interchangeability of the probes and forms a good
basis for the continuous measurements with good traceability.
The GMK220 can be used to calibrate the probes marked with a little
star (*) in the probe label. A little star indicates that the probe has the
program version compatible with the calibrator.
VAISALA _____________________________________________________________________________3
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1. Probe to be checked (not
GMK220 Calibrator for the GMP220 Series
Probes
included)
2. Probe connector and the
cable
3. Rotameter
4. Flow adjustment screw
5. Chamber (including 0-ring
18.3x2.4 NBR 70 ShA,)
6. Gas inlet
7. Gas outlet
8. Serial cable (connects
calibrator and PC)
9. 24 V Supply voltage in (+)
10. Ground (-)
CAUTION
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Figure 1 GMK220 Calibrator.
When handling the GMK220 calibrator, please be careful not to
damage the board on the backside of the plate.
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Chapter 2______________________________________________________________Product description
Additional equipment
The following additional equipment is needed for checking and
calibration operations:
• Traceable reference gas/es as follows:
spot checking: one gas with CO2 concentration within the
measuring range of the probe. Accuracy shall be 1% (or better).
two-point calibration: two gases with CO2 concentrations
representing the low and high end of the probe's measuring range.
See the requirements below.
• Pressure regulator (giving about 1 bar pressure)
• PC and a terminal software (e.g. Windows® Hyper Terminal)
• Power supply, 24 VDC/1A
In addition, values on the ambient temperature (with accuracy of ± 0,5
ºC) and barometric pressure (with accuracy of ± 1 hPa) are needed as
input data during the checking or calibration procedure.
Requirements for the calibration gases
Low end
calibration gas
High end
calibration gas
N2 gas with a purity of N50 (or better).
Traceable to appropriate standards (for
example NIST).
Mixture of CO2 and N2 gases
CO2 concentration shall be 95...105 % of the
measuring range of the probe. Accuracy shall
be 1 % (or better). Traceable to appropriate
standards (for example NIST).
.
VAISALA _____________________________________________________________________________5
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CHAPTER 3
OPERATION
Spot checking
Spot checking is carried out when there is a need to check if the probe (GMP221
or GMP222) is operating correctly. The reference gas concentration must be
within the measuring range of the probe to be checked. Please read requirements
concerning the reference gases from Chapter2 Additional equipment before
starting the operation.
Perform the spot checking according to the following instructions:
1. Connect the cable (item 2, Figure 1) to the probe to be tested.
2. Insert the probe into the chamber (item 5, Figure 1) so that the
perforated filter cover is completely inside the chamber
3. Connect the PC to the calibrator with the serial cable (item 8,
Figure 1). Check the connection set-up, the serial line settings for data
transfer shall be
• 9600 baud
• parity: 8/None
• 1 stop bits
4. Connect the 24 VDC supply power to the connectors (items 9 and
10, Figure 1).
5. The following (or similar) text appears in the terminal window on
the PC screen (program version number can be updated):
GMT220A - Version: STD 4.08
Copyright: Vaisala Oyj,1997-2000
>
>
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Chapter 3_____________________________________________________________________ Operation
6. Let the calibrator settle for 10 minutes.
7. Connect the reference gas and adjust the flow rate to 0.6 l/min
with a screwdriver (item 4, Figure 1). Flush the chamber with the gas
for 5 minutes.
8. Input the ambient barometric pressure.
MF_PRESSURE XXXX<CR>
where xxxx= pressure in hPa.
Example:
>MF_PRESSURE 1013<cr>
MF_PRESSURE=1013
>
9. Input the ambient temperature.
MF_TEMP XXX<CR>
where xxx = temperature is given in tenths of °C (25 °C = 250).
Example:
>MF_TEMP 250 <cr>
MF_TEMP=250
>
10. List the carbon dioxide concentration.
MF_MODE 2<CR>
Example:
>MF_MODE 2<cr>
MF_MODE=2
1620.1
1618.3
1619.8
1619.8
...
The carbon dioxide concentration (in ppm) is measured every 0.5
seconds.
VAISALA _____________________________________________________________________________7
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11. Stop the output with the ESC-button (or by typing MF_MODE 0).
12. The difference between the average reading and the actual
concentration of the reference gas shall be within the long term
stability specifications of the probe. If there is need for calibration,
please refer to the chapter Two- point calibration.
13. Disconnect the gas flow and remove the probe from the chamber.
NOTE
If the error of the output reading for some reason is more than 20%,
please send the probe to Vaisala for service.
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Chapter 3_____________________________________________________________________ Operation
Two-point calibration
The reference gases used for the two-point calibration shall represent the low
and high end of the probe's measuring range. Please, read recommendations
concerning the reference gases in Chapter 2 Additional equipment before
starting the operation.
Perform the two-point calibration according to the following
instructions:
1. Connect the cable (item 2, Figure 1) to the probe to be tested.
2. Insert the probe into the chamber (item 5, Figure 1) so that the
perforated filter cover is completely inside the chamber.
3. Connect the PC to the calibrator with the serial cable (item 8,
Figure 1). Check the connection set-up, the serial line settings for data
transfer shall be
• 9600 baud
• parity: 8/None
• 1 stop bits
4. Connect the 24 VDC supply power to the connectors located on
the right-hand side of the plate (items 9 and 10, Figure 1).
5. The following (or similar) text appears in the terminal window on
the PC screen (number of the program version can be updated):
GMT220A - Version: STD 4.08
Copyright: Vaisala Oyj, Matti Kokki, 1997-2000
>
6. Let the calibrator settle for 10 minutes.
7. Connect the low-end gas and adjust the flow rate of 0.6 l/min with
a screwdriver (item 4, Figure 1). Flush the chamber with the gas for 5
minutes.
8. Give the password by typing
PASSWORD 5120<CR>
VAISALA _____________________________________________________________________________9
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9. Give the input data for the calibration.
CALICALI L <sample quantity><CO2 concentration >
<P
ambient
><T
ambient
><cr>
NOTE
where CO2 concentration is given in ppm, P
hPa and T
is temperature given in °C.
ambient
is pressure given in
ambient
The sample quantity determines the number of measurements of
which averages are calculated. The sample quantity is recommended
to be at least 200.
The character after the CALICALI command is case-sensitive i.e. it has
to be given as capital letter (CALICALI L).
Example:
>CALICALI L 200 0 1013 23<cr>
Calibration start - Length is 200 samples (it takes
about 107 seconds)
You can interrupt operation by CTRL-C
1297.5 550.4 382.7 445.5 32.5
1295.2 554.5 482.0 445.9 32.5
...
1298.1 561.7 603.5 449.6 32.5
1296.9 557.3 523.4 454.2 32.5
Noise measurement ready
Res Avg = 470.491219
Res Std = 82.244873
FR Avg = 447.789145
FR Std = 2.355181
Rx Avg = 1296.441917
Rx Std = 1.870829
Tx Avg = 554.371452
Tx Std = 3.844639
Low gas ( 0 ppm) measurement done. Start high gas.
>
10. As the calibration at low end is completed, the software asks to
change to the high gas.
11. Adjust the flow rate of the high end gas to 0.6 l/min with a
screwdriver (item 4, Figure 1). Flush the chamber with the gas for 5
minutes.
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Chapter 3_____________________________________________________________________ Operation
12. Give the input data for the calibration.
CALICALI H <sample quantity><CO2 concentration >
<P
ambient
><T
ambient
><cr>
NOTE
where CO2 concentration is given in ppm, P
T
is given in °C.
ambient
is given in hPa and
ambient
The sample quantity determines the number of measurements of
which averages are calculated. The sample quantity is recommended
to be at least 200.
The character after the CALICALI command is case-sensitive i.e. it has
to be given as capital letter (CALICALI H).
Example:
>CALICALI H 200 30000 1013 25<cr>
Calibration start - Length is 200 samples (it takes
about 107 seconds)
You can interrupt operation by CTRL-C
1139.3 1219.3 1.0 1.4 32.5
1137.6 1217.3 1.0 1.3 32.5
...
1137.7 1219.7 1.0 1.1 32.5
1137.0 1216.8 1.0 1.1 32.5
Noise measurement ready
Res Avg = 0.999947
Res Std = 0.001777
FR Avg = 1.165917
FR Std = 0.101676
Rx Avg = 1138.306737
Rx Std = 1.732051
Tx Avg = 1218.396783
Tx Std = 1.837117
PC_METHOD=3
PC_R0=1138.306737
PC_T0=485.501432
PC_RS=1138.306737
PC_TS=1958.435059
High gas ( 30000.0 ppm) ready. Two point calibration
completed.
>
13. As the calibration is completed, save the calibration parameters to
the non-volatile memory in the probe.
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PROBE_SAVE<CR>
>PROBE_SAVE<cr>
New calibration parameters are now saved in the probe.
14. Disconnect the gas flow and remove the probe from the chamber.
After two-point calibration it is recommended to ensure the correct operation of
the probe by carrying out a spot checking procedure using both low and high end
gases. The readings should be within the accuracy specifications of the
transmitter.
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Chapter 4_________________________________________________________________ Technical data
CHAPTER 4
TECHNICAL DATA
Operating temperature range +15...30ºC
Dimensions 20 x 18 x 16 (height) cm
Materials
Metal frame
Probe chamber
Transmitter body
Weight about 2,5 kg
Supply voltage 24 VDC
Anodised aluminium
POM plastic
ABS plastic
VAISALA ____________________________________________________________________________13
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*U421
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