The DH3 Series Digihelic differential pressure controller from Dwyer Instruments Inc., Michigan City, IN, provides a 4–20 mA output, 2 SPDT relays with adjustable deadbands, and a large backlit LCD. The sensing element can detect low differential pressures down to 0.25 in.w.c. up to 100 in.w.c.; bidirectional ranges are also available. You can program the device from its menu key and select security level; set point or set point and alarm operation; auto or manual reset; engineering units; pressure, velocity, or flow operation; K-factor; and duct size for volumetric flow operation. The gauge-style housing is NEMA 4X rated.
Dwyer Instruments Inc.