Figaro - Model TGS821 - Hydrogen Sensor - Brochure

The sensing element of Figaro gas sensors is a tin dioxide (SnO2) semiconductorwhich has low conductivity in clean air.  In the presence of a detectable gas, thesensor`s conductivity increases depending on the gas concentration in the air.  Asimple electrical circuit can convert the change in conductivity to an output signalwhich corresponds to the gas concentration.The TGS 821 has high sensitivity and selectivity to hydrogen gas.  The sensor candetect concentrations as low as 50ppm, making it ideal for a variety of industrialapplications.