How do Solid State Refrigerant Leak Detectors work?

[tigerstyle]

Sorry for the poor forum etiquette, but this seems like the best way to ask...

I have done my research and have found that refrigerant leak detectors (sniffers) use a solid state sensor to detect gas leakage, and that other types are available: http://www.skateisi.com/site/_print.cfm?content=archive_gasleakdetector ultrasonic, dies, UV detection, flame detection etc.

But the best seems solid state, the Javac model can detect down to 2 grams per year! http://www.javac.co.uk/automotivehandheld/705-202-g21-tek-mate-leak-detector/

My question is really about the solid state sensors, is this priority technology that Javac and similar have developed? Or would it be off the shelf parts from DigiKey/Farnell? I can't get the right search term to google to read further on the sensor specs.

Many thanks, love the show!

[N2IXK]

Here is the page of a manufacturer of such things, which contains links to datasheets and info on the different technologies used for various gases.

http://www.figarosensor.com/

For common refrigerant gases, look under "halocarbon" section...

[tigerstyle]

That's perfect, many thanks!