We can calculate wobbe index using relative density (S.G.) measurement in conjunction with AGA5. The calculation is relatively simple but depends on the CO2 and N2 content. In some applications gas quality is extremely variable as
some components are stripped out as feedstocks and the residual gas used as fuel. This means that using periodic analysis for CO2 and N2 content is unreliable so we wish to include CO2 and N2 sensors transmitting 4-20mA signals. The sensors should be suitable for a hazardous area i.e. ATEX, CSA etc. required. Any suggestions for suppliers please?

 

Licor ( "http://env.licor.com":http://env.licor.com ) makes several different CO2 Analyzers. These may
be a bit much for your application, they are very precise. You'll have to ask them about using it in haz. locations. One thing to note is that any NDIR measurement is very pressure sensitive.
As for N2, there are several chemical methods for measuring N2, but I don't know of any commercial sensors.

Matt Warshawsky
http://www.azeotech.com

 

We are a manufacturer of infrared CO2 sensors. We do not currently offer products in explosion proof housing, however we have an accessory industrial housing and also make an OEM sensor module that could be mounted in a more rugged package. Check out our website at "www.telaire.com":http://www.telaire.com for further info.

 

You may like to check with SenseAir AB of Sweden. They produce very good CO2 sensors. The web address is "www.senseair.com":http://www.senseair.com or write to "[email protected]", mailto:[email protected]