The Series 616D Differential Pressure Transmitter senses the pressure of air and compatible gases and sends a standard 4-20 mA output signal. The 616D housing is specifically designed to mount on a 35 mm DIN rail in a panel. This mounting style allows for several units to be mounted closely together reducing required space. A wide range of models are available factory calibrated to specific ranges. The span and zero controls are for use when checking calibration. They are not intended for re-ranging to a significantly different span. Versatile circuit design enables operation in 2-wire current loops.