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dwyer series 475 mark iii handheld digital manometer

Dwyer Series 475 Mark III Handheld Digital Manometer

Dwyer Series 475
Series 475 Mark III

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

THE DWYER SERIES 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 in 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 gage. See the complete 475-1-AV kit.

The Series 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 in w.c. range is compensated for position sensitivity through the use of a unique patented dual sensor system. A standard 9 V 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 set-up 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″ ID vinyl or rubber tubing. Complete instructions are conveniently printed on rear of housing.


  • Service:Air and compatible combustible gases.
  • Wetted Materials:Consult factory.
  • Accuracy:±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).Display:0.42″ (10.6 mm) 4-digit LCD.
  • Resolution:See Ordering page.
  • Power Requirements:9 V alkaline battery, installed non-functional, user replaceable.
  • Weight: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:CE.


  • New Low Range Option 0-1.000 in. w.c.
  • Measures Positive, Negative and Differential Pressures
  • Rugged, Extruded Aluminum Case
  • Lightweight, Fast and Easy to Use
  • Selectable English/Metric Units


  • -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.


  • Field calibration.
  • Monitoring or trouble shooting HVAC systems.
  • Clean room checks.
  • Air velocity monitoring with Dwyer Pitot tube.
  • Natural gas appliance line pressure.


475-0-FM 0-10.00" w.c. (2.491 kPa)5 psigHandheld
475-00-FM0-4.000" w.c. (0.996 kPa)5 psigHandheld
475-000-FM0-1.000" w.c. (.2491 kPa)5 psigHandheld
475-1-FM0-20.00" w.c. (4.982 kPa)10 psigHandheld
475-2-FM0-40.00" w.c. (9.96 kPa)10 psigHandheld
475-3-FM0-200.0" w.c. (49.82 kPa)30 psigHandheld
475-4-FM0-10.00 psi (.6895 bar)30 psigHandheld
475-5-FM0-20.00 psi (1.379 bar)60 psigHandheld
475-6-FM0-30.00 psi (2.069 bar)60 psigHandheld
475-7-FM0-100.0 psi (6.895 bar)150 psigHandheld
475-8-FM0-150.0 psi (10.34 bar)200 psigHandheld
475-0-FM-AV0-10.00" w.c. (2.491 kPa)5 psigKit
475-00-FM-AV0-4.000" w.c. (0.996 kPa)5 psigKit
475-1-FM-AV0-20.00" w.c. (4.982 kPa)10 psigKit
475-1T-FM-AV0-20.00" w.c. (4.982 kPa)10 psigKit

** kit includes static pressure tips, rubber tubing, Pitot tube, step drill, air velocity slide chart and carrying case.