The CO transmitter monitors carbon monoxide [CO] levels and is intended to be used for the continuous monitoring of vehicle exhaust in non-hazardous areas. The CO uses a wide spectrum, long life electrochemical sensor to measure the amount of carbon monoxide in the environment. Both the Room and Duct CO transmitters are offered in a standard NEMA 1 rated ABS Polycarbonate plastic enclosure. An optional NEMA 4X watertight and dust proof enclosure is only available with the CO room transmitter. Other options include an LCD display with [2] SPDT Form 1C relays and a buzzer.