The series U single and multichannel wall-mounted gas monitor uses unique, patented sensors that are highly specific, fast responding, poison resistant and unaffected by moisture or temperature changes. Sensors are available for hydrocarbons, freons, ethylene oxide, alcohols, diesel/gasoline vapors, hydrogen, ammonia, sulfur dioxide, hydrogen sulfide, carbon monoxide, combustibles and other gases. Ranges are available to detect these gases in the low-ppm, high-ppm or %LEL levels without sensor damage. The compact, easy-to-operate unit includes user-adjustable alarms, relay contacts and recorder outputs.