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  • For use with air and compatible combustible gases
  • Measures positive, negative and differential Pressures
  • Ranges from 0-1.000 in. w.c. to 0-150 psi
  • Accurate up to ±0.5% F.S. (60 to 78°F)
  • Pressure Hysteresis: ±0.1% of full scale
  • Temperature compensated from 32 to 104°F
  • Connections:
    • Two barbed connections for use with 1/8" or 3/16" I.D. tubing.
    • Two compression fittings for use with 1/8" I.D. x 1/4" O.D. tubing (for 475-7 & 475-8)
  • 4 digit LCD display
  • Rugged, extruded aluminum case
  • Lightweight, fast and easy to Use
  • CE, FM Approved


The Dwyer 475 Mark III Handheld Digital Manometer is ideal for field calibration, monitoring or trouble shooting HVAC systems, clean rooms or a wide range of other low pressure pneumatic systems. This handy instrument measures positive, negative or differential pressures of air and natural gases in ranges from 1" w.c. (0.249 kPa) to 150 psid (10.34 bar). Its simple operation and easy to read digital display make it an indispensable test instrument for the plant engineer, industrial hygienist and HVAC technician. When used with a Dwyer Pitot tube, the Series 475 Mark III can also be used as an air velocity gauge. The Dwyer 475 is approved and is intrinsically safe for hazardous locations, Class 1, Div.1, Group A, B,C, D, T4.

The Dwyer 475 Mark III is housed in a durable extruded aluminum case with its solid state circuitry mounted on a tough fiberglass epoxy circuit board. To meet the most demanding applications and to provide stability of instrument reading, the 1" w.c. range is compensated for position sensitivity through use of a unique dual sensor system. A standard 9 volt battery provides up to 100 hours of operation. Dual push pads on the front panel control on-off, auto zero, and pressure unit selection. No setup or leveling. The large 0.42" LCD display is easy to read, minimizing data collection errors. Units include a "low battery" indicator. The pressure sensor used is a highly stable silicon piezoresistive device. Standard connections are dual sized for 1/8" or 3/16" I.D. vinyl or rubber tubing. Complete instructions are conveniently printed on rear of housing.

The Dwyer 475 is also available in a convenient, all-in-one kit. The small, light and easy to use kit includes a pitot tube, two static pressure tips with magnetic mounting to measure pressure drop across filters, condenser coils, etc. Also includes are rubber tubing, 9V battery, step drill, AV calculator slide rule, and custom fitted carrying case.


This product can be used in the following applications: