The model SM95 sensor transmitter is housed in an explosion-proof casing and operates on 14-24 VDC power. The SM95 has been UL Classified and CSA Approved Class I, Div. 1, Groups B, C, and D. The SM95 provides a 4-20 mA linear output proportional to the gas concentration and is calibrated by adjusting potentiomenters located inside the housing. The SM95 can operate as a stand-alone instrument, or it can be used in conjunction with any of IST's complete line of control units which provide control room readings and alarm relays. When used with any of IST's MP Series control units, automated calibration is provided, enabling calibration without the need to adjust potentiometers. Like the 4-20 IQ, the SM95 can be used with any of IST's sensor technologies: infra-red (IR), solid state, catalytic bead, or electrochemical.