• Air and non-combustible, compatible gases
  • Die cast aluminum case and bezel housing materials
  • Ranges:
    • 0 to 0.25 up to 0 to 100 inH2O
    • -0.25 to 0.25 up to to -10 to 10 inH2O (bi-directional)
  • Accuracy:
    • ±1.5% for 0.25" and ±0.25˝ w.c. ranges
    • ±1% 0.5" to 5" w.c. and corresponding bi-directional (except ±2.5˝ w.c.)
    • ±0.5% all other ranges
  • Process connection: 1/8" female NPT, (side or back connection)
  • 15 pin male high density D-sub connection
  • 18" (46cm) cable with 10 conductors included


The Dwyer DH3 Digihelic Differential Pressure Controller is a 3 in 1 instrument possessing a digital display gauge, control relay switches, and a transmitter with current output all packed in the popular Photohelic gauge 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 in w.c. to 2.5 in w.c. full scale. Ranges of 5 in 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.

Applications for the DH3 include:

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