Series 621 Pressure Indicator is a 1/8 DIN measuring and controlling instrument designed for positive, negative or differential pressures of air and compatible gases. Pressure readings are displayed on a large 3-1/2 digit LCD display which unit simultaneously produces a standard 4-20 mA output signal. Over a dozen stocked ranges are available from 0-3 in. w.c. to 0-100 psid or choose metric units in ranges from 0-0.75 kPa to 0-690 kPa. Circuit design enables use in 2-wire current loops.