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  • Air and non-conductive gases
  • ±0.8% FS accuracy
  • Ranges from 0.1 to 100 in w.c.
  • 0 to 170°F operating temp
  • 15 psig (1.0 bar) pressure limit
  • Unidirectional and bi-directional pressure ranges
  • Compact, lightweight design


The Dwyer 668B/D Differential Pressure Transmitters are capable of sensing differential gauge pressure with ±0.8% FS accuracy, and converts this pressure difference to a proportional high level analog output for both unidirectional and bi-directional pressure ranges. These transmitters can withstand up to 15 psig overpressure with no damage to the unit. The compact, lightweight design makes installation simple and easy. Units are protected against incorrect wiring, and include a protective terminal cover.

Applications for the 668B/D include:

  • HVAC and VAV control
  • Clean rooms and isolation rooms
  • Duct static pressure measurement