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Last Updates: 28/11/2020

Dwyer Series DH3 Digihelic® Differential Pressure Controller

The Dwyer Series DH3 Digihelic® Differential Pressure Controller is a 3-in-1 instrument possessing a digital display gage, control relay switches, and a transmitter with current output all packed in the popular Photohelic® gage style housing. Combining these 3 features allows the reduction of several instruments with one product, saving inventory, installation time and money. The Digihelic® controller is the ideal instrument for pressure, velocity and flow applications, achieving a 1% full scale accuracy on ranges down to the extremely low 0.25″ w.c. to 2.5″ w.c. full scale. Ranges of 5″ w.c. and greater maintain 0.5% F.S. accuracy. Bi-directional ranges are also available.

The Series DH3 Digihelic® controller allows the selection of pressure, velocity or volumetric flow operation in several commonly used engineering units. 2 SPDT control relays with adjustable deadbands are provided along with a scalable 4-20 mA process output.

Programming is easy using the menu key to access 5 simplified menus which provide access to: security level; selection of pressure, velocity or flow operation; selection of engineering units; K-factor for use with flow sensors; rectangular or circular duct for inputting area in flow applications; set point control or set point and alarm operation; alarm operation as a high, low or high/low alarm; automatic or manual alarm reset; alarm delay; view peak and valley process reading; digital damping for smoothing erratic process applications; scaling the 4-20 mA process output to fit your applications range and field calibration.

Product Applications

  • SCFM flow in ducts
  • Filter status
  • Static pressures in ducts or buildings
  • Damper control
  • Fan control

Service : Air and non-combustible, compatible gases.

Wetted Materials : Consult factory.

Housing Material : Die cast aluminum case and bezel.

Accuracy : ±1.5% for 0.25″ and ±0.25″ w.c. ranges. Ranges 0.5″ to 5″ w.c. and corresponding bi-directional (except ±2.5″ w.c.) ±1%; All other ranges: ±0.5% @ 77°F (25°C) including hysteresis and repeatability (after 1 hour warm-up).

Stability : < ±1% per year.

Pressure Limits : Ranges ≤ 2.5 in w.c.: 25 psi; ±2.5″, 5 in w.c.: 5 psi; 10 in w.c.: 5 psi; 25 in w.c.: 5 psi; 50 in w.c.: 5 psi; 100 in w.c.: 9 psi.

Temperature Limits : 32 to 140°F (0 to 60°C).

Compensated Temperature Limits : 32 to 140°F (0 to 60°C).

Thermal Effects : 0.020%/°F (0.036/°C) from 77°F (25°C). For 0.25″ and ±0.25″ w.c. ranges: ±0.03%/°F (±0.054%/°C).

Power Requirements : 12 to 28 VDC, 12 to 28 VAC 50 to 400 Hz.

Power Consumption : 3 VA max. Output Signal : 4 to 20 mA DC into 900 Ω max.

Zero & Span Adjustments : Accessible via menus.

Response Time : 250 ms (damping set to 1).

Display : Backlit 4 digit LCD 0.4″ height LED indicators for set point and alarm status.

Electrical Connections : 15 pin male high density D-sub connection. 18″ (46 cm) cable with 10 conductors included.

Process Connections : 1/8″ female NPT. Side or back connections.

Mounting Orientation : Mount unit in vertical plane.

Size : 5″ (127 mm) OD x 3-1/8″ (79.38 mm).

Weight:1.75 lb (794 g).

Agency Approvals : CE.

SWITCH SPECIFICATIONS

Switch Type : 2 SPDT relays.

Electrical Rating : 1 A @ 30 VAC/VDC.

Set Point Adjustment : Adjustable via keypad on face.

  • 3-in-1 instrument allows the reduction of several instruments with one product, saving inventory, installation time and money
  • Full scale accuracy of 1% even on extremely low ranges, and 0.5% for ranges above 5 in w.c. provide for greater measurement precision
  • Secure menu program provides access to device operation only for the right skill level

Manual: Instruction Manual DH3
Catalog Page: Series DH3 Catalog Page
Product Data Sheet: DH3 Datasheet

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