The Dwyer Digihelic Series Differential Pressure Controller is a 3-in-1 instrument possessing a digital display gauge, control relay switches, and a transmitter with current output. The Digihelic controller is the ideal instrument for pressure, velocity and flow applications, achieving a 0.5% full scale accuracy on ranges from 0.25 to 100 in w.c. The Digihelic controller allows the selection of pressure, velocity or volumetric flow operation in several commonly used engineering units. Two SPDT control relays with adjustable dead bands are provided along with a scalable 4-20 mA process output. The Series DH provides extreme flexibility in power usage by allowing 120/220 VAC and also 24 VDC power which is often used in control panels.