The recently released EX-5165 Sensor/Transmitter from ENMET Corp. is a three-wire 4-20 mA sensor for the detection of carbon dioxide in ranges from 0 to 500 ppm and 0% to 100% by volume. It also features a 24 VDC loop-powered transmitter. The nondispersive infrared sensor continuously monitors high concentrations of the gas, and it can operate in an anaerobic environment. The device provides an LCD of carbon dioxide concentration and has three LED alarm point indicators. EX-5165 is meant to be used in conjunction with an appropriate power supply and any one of several controllers available from ENMET. It is approved for location in Class I, Division 1, Groups B, C, and D atmospheres. (