Dwyer Series 475 Mark III Handheld Digital Manometer


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Dwyer Series 475 Mark III Handheld Digital Manometer

Ranges from 1" w.c. to 150 psid, ±0.5% Accuracy

The SERIES 475 Mark III Handheld Digital Manometer measures positive, negative, or differential pressures of air and natural gases in ranges from 1 in w.c. (0.249 kPa) to 150 psid (10.34 bar). The dual push pads on the front panel control the on/off, auto zero, and pressure unit selection, allowing for simple operation with no set up needed. When used with a Dwyer® Pitot tube, the Series 475 can also be used as an air velocity gage.

Product Applications

  • Monitoring natural gas pressures on boilers and other combustion equipment
  • Air velocity monitoring, when used with a Dwyer® Pitot tube and AV calculator
  • Field calibration of other instruments
  • Monitoring or troubleshooting HVAC systems


Air and compatible combustible gases.
Wetted Materials:
Consult factory.
±0.5% Full Scale, 60 to 78°F (15.6 to 25.6°C); ±1.5% Full Scale from 32 to 60°F and 78 to 104°F (0 to 15.6°C and 25.6 to 40°C).
Pressure Hysteresis:
±0.1% of Full Scale.
Pressure Limits:
See catalog page.
Temperature Limits:
0 to 140°F (-17.8 to 60°C).
Compensated Temperature Limits:
32 to 104°F (0 to 40°C).
Storage Temperature Limits:
-4 to 176°F (-20 to 80°C).
0.42" (10.6 mm) 4-digit LCD.
See Ordering page.
Power Requirements:
9 V alkaline battery, installed non-functional, user replaceable.
10.8 oz. (306 g).
Process Connections:
Two barbed connections for use with 1/8" (3.18 mm) or 3/16" (4.76 mm) I.D. tubing. Two compression fittings for use with 1/8" (3.18 mm) I.D. x 1/4" (6.35 mm) O.D. tubing for 475-7 & 475-8 only.
Agency Approvals:


  • Rugged aluminum case protects instrument from damage during transport/use
  • Large, easy to read LCD and simple operation
  • FM approved to be intrinsically safe in hazardous locations, Class 1, Div 2, Groups A, B, C, D, T4 Ta = 70°C


  • -AV Kit includes Model 475 Digital Manometer, Pitot Tube, two No. A-303 static pressure tips with magnetic mounting, 3/16" I.D. rubber tubing, No. A-397 step drill for 3/16" - 1/2" holes in 1/16" increments, No. A-532 AV slide chart, 9 volt battery, and fitted polyethylene case.

Product Literature


Catalog Pages

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  • Dwyer Series 475 Mark III Handheld Digital Manometer