The refrigeration housecarbon monoxide model no cmt200 series cmt200 carbon monoxide transmitter provides a field selectable current or voltage output that is proportional to the level of gas present in underground parking garages, Or mechanical rooms, Vehicle maintenance facilities. A electrochemical sensor, Field replaceable provides accurate readings for as long as 4 years with proper calibration. Field calibration can be done by using model gck, 200co, 2000co2 model a, Calibration gas, 507a and the, Calibration adapter on board span and zero potentiometers. Application garage ventilation mechanical room monitoring features field selectable current or voltage outputs replaceable sensor field calibration kits