www.safetyandhealthmagazine.com/articles/hydrogen-gas-detector-2

Hydrogen gas detector

June 1, 2011
The TS4000H Intelligent Hydrogen Gas Detector accurately detects hydrogen at 0-500 ppm levels, and has a precision sensor with a T90 response of less than 30 seconds and minimal zero shift across its operating environmental conditions. All electronics are contained within explosion-proof housing, so gas sensor information can be processed at the sensor site. 

General Monitors