Series 477 Handheld Digital Manometer

When working in poorly lighted areas, just switch on the handy backlight feature. It automatically shuts itself off after 20 minutes to minimize battery drain. Electronic zeroing means you simply touch a single key to perfectly null out any minor pressure differences. A display HOLD key freezes the current pressure for those all-too-common situations where readings fluctuate. We even included an audible alarm to warn you of overpressure plus a visual alarm also confirms a value has been stored, eliminating the need to observe display during a duct traverse.

• Field calibration.

• Monitoring or trouble shooting HVAC systems.

• Clean room checks.

• Air velocity monitoring with Dwyer Pitot tube.

• Natural gas appliance line pressure


  • Service: Air and compatible gases. FM models: air and compatible combustible gases.
  • Wetted Materials: Consult Factory.
  • Accuracy: ±0.5% F.S., 60 to 78°F (15.6 to 25.6°C); ±1.5% F.S. 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.
  • Response Time: 1 second.
  • Resolution: See catalog page.
  • Power Requirements: 9 V alkaline battery, included, user replaceable.
  • Weight: 10.2 oz (289 g).
  • 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 477-7-FM & 477-8-FM only.
  • Agency Approvals: CE, FM.


• New Low Pressure Ranges.

• New USB Option Comes with Cable and Software for Easy Data Downloading.

• Instant Selection from up to Nine English/Metric Units.

• Stores 40 Readings in Memory for Later Reference.

• Measures Positive, Negative or Differential Pressures.

• Large Easy-to-Read 0.4″ LCD Display Includes Switchable Backlight for Great Visibility – Anywhere!

• Both Audible and Visual Overpressure Alarms.

• Includes + and – Indicators plus Low Battery Warning.

• Operates up to 100 Hours on a Single 9 Volt Battery.