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Hi All,
We are using Luft Detector type Infra Red analyser to measure CO (0-200 ppm) in
following background gases. The normal concentration of the CO in the process is
around 10-12 ppm.
CO2 7.12 %
Ethylene 23.0 %
Ethane 0.48 %
O2 4.11 %
Argon 9.76 %
N2 2.53 %
Methane 51.4 %
Ethylene Oxide 2.07 %
Moisture 1.76 %
Acetaldehyde 0.002 %
We calibrate the analyser with following calibration gases.
Zero gas : N2 - 8.5%, Ethylene - 25%, CO2 - 5%, Argon - 6%, Ethane -
0.5%, Methane - Balance (55%)
Span gas : CO - 200 ppm balance above zero gas.
With the help of above calibration gases we are able to calibrate the analyser, but it shows higher value in the process sample viz. it shows 50 ppm CO instead of 12 ppm.
This means that there is a interference of some background gases. We want to know which of the above listed components interfere with CO measurement and to which extent. ( e.g. 20% CO2=2ppm CO etc.)
The reference cell is filled with the Zero gas and then sealed. We want to make it "FLOW THROUGH" reference with process sample itself less CO component, so that it will be TRUE CO measurement with interference of all the background gases nullified. To achieve this we have to remove the CO from the process sample. Does anybody know the method to remove the CO from the above process sample (without affecting the other background gases.) or convert it to CO2 or other gas which does not interfere with CO measurement.
Alternately, I would like to know which type of analyser will be best suitable for above application.
Thanks in advance.
Regards
Manoj Topiwala
We are using Luft Detector type Infra Red analyser to measure CO (0-200 ppm) in
following background gases. The normal concentration of the CO in the process is
around 10-12 ppm.
CO2 7.12 %
Ethylene 23.0 %
Ethane 0.48 %
O2 4.11 %
Argon 9.76 %
N2 2.53 %
Methane 51.4 %
Ethylene Oxide 2.07 %
Moisture 1.76 %
Acetaldehyde 0.002 %
We calibrate the analyser with following calibration gases.
Zero gas : N2 - 8.5%, Ethylene - 25%, CO2 - 5%, Argon - 6%, Ethane -
0.5%, Methane - Balance (55%)
Span gas : CO - 200 ppm balance above zero gas.
With the help of above calibration gases we are able to calibrate the analyser, but it shows higher value in the process sample viz. it shows 50 ppm CO instead of 12 ppm.
This means that there is a interference of some background gases. We want to know which of the above listed components interfere with CO measurement and to which extent. ( e.g. 20% CO2=2ppm CO etc.)
The reference cell is filled with the Zero gas and then sealed. We want to make it "FLOW THROUGH" reference with process sample itself less CO component, so that it will be TRUE CO measurement with interference of all the background gases nullified. To achieve this we have to remove the CO from the process sample. Does anybody know the method to remove the CO from the above process sample (without affecting the other background gases.) or convert it to CO2 or other gas which does not interfere with CO measurement.
Alternately, I would like to know which type of analyser will be best suitable for above application.
Thanks in advance.
Regards
Manoj Topiwala