The Dwyer 616D Differential Pressure Transmitter senses the pressure of air and compatible gases and sends a standard 4 to 20 mA or 0 to 10 VDC output signal. The 616D enclosure 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. The span and zero controls are for use when checking calibration. They are not intended for re-ranging. Versatile circuit design enables operation in 2-wire current loops.