ENMET CORP. The EX-6100, 24 VDC, combustible gas sensor/transmitter utilizes a matched pair of catalytic elements. The sensor can be calibrated for 0-100% LEL hydrogen, methane, propane, butane or other combustible hydrocarbons. Features include an internal-alarm-relay PC board, two inlet/outlet parts, plug-in sensor, liquid crystal display and non-intrusive calibration. It is certified to international standards.