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H2 Sensor from Brechbuhler
Posted: Thu Apr 08, 2010 7:15 pm
by tmv69
I am using H2 as a carrier gas and the new regulations in my lab require a H2 sensor. We purchased one from Brechbuhler but it does not seem to work the way we expected (we might have wrong expectations though).
We have the passive system and it seems that even with a column disconnected from the detector end and the flow set to 8ml/min the sensor does not register anything when the GC is on stand by. During a run, when the temp changes and the gas “starts moving aroundâ€
Posted: Fri Apr 09, 2010 10:14 am
by CE Instruments
You purchased the passive sensor , for this to work you need a positive air pressure in the oven which will only happen with the fan on. You do not state what you mean by stand by. Most GCs will always have the oven fan on while the GC is in stand by mode just at a low oven temperature. If you have set the oven to off but the carrier to on you have created a condition in which there is no flow in the oven and it will make it difficult for a passive sensor to work. Have you contacted your suplier to discuss this with them ? An active version is also available for systems that do not maintain positive pressure.
Posted: Tue Apr 13, 2010 3:42 pm
by tmv69
The stand-by is with the oven on and fan working. Also there should be some positive pressure from the stand-by temperature being above ambient temperature. After making some calculations I realized that it will take a long time to reach the 1% limit for wich the sensor is set. So I think the sensor is actually doing what it should.
Unfortunately in the States, the vendor rep is very unresponsive and you have to practically beg to get any information out!
Thanks for the input!