Brandt Instruments Representing Dwyer 477-FM Intrinsically safe differential pressure & velocity meters, PDM, Pitot Probes

Distributing Dwyer Instruments

Dwyer 477-FM Portable Digital Manometers, Intrinsically Safe PDM, Differential Pressure, Velocity Meters with pitot probes

Dwyer 477AV Portable Digital Manometers

Differential Pressure and Velocity Meters

CE and FM Mark Symbols

Dwyer Series 477AV Intrinsically Safe Portable Digital Micromanometers - PDM -

The Dwyer Series 477AV Digital Manometers
with ±0.5% Accuracy

The Series 477AV portable digital micromanometers (PDM) are packed with features you need to make low pressure measurement and recording faster, easier and more accurate than ever. You can instantly select from up to nine of the most widely used pressure units without having to waste time and risk mistakes with tedious conversions.

      Dwyer 477AV PDM Features:

  •  11 models with several basic ranges from 0-20" H2O up to 0-150 psi
  •  Large easy-to-read 0.4" LCD display
  •  Includes switchable backlight for great visibility
  •  9 switchable pressure units: psid, inch H2O, mm H2O, inch Hg, mmHg, kPa, Pa, bar, mbar
  •  Measures Positive, Negative or Differential Pressures
  •  Electronic zeroing
  •  ±0.5 % full-scale value
  •  Display HOLD key freezes pressure readings for ease of use
  •  Stores 40 readings in memory
  •  Includes + and - indicators plus low battery warning
  •  Both audible and visual overpressure alarms
  •  Operates up to 100 hours on a single 9 volt battery


    Dwyer 477AV PDM Applications:

  •  Measurement of system pressures in heating, ventilation and air conditioning  (HVAC) systems
  •  Perfect for HVAC technicians performing Pitot tube traverses of airflow readings across a duct
  •  Monitoring differential pressure across filters and coils in HVAC systems
  •  Measuring positive and negative pressure in air conditioning ducts
  •  Measuring differential pressure for clean room monitoring

Dwyer 477AV Manometer Models

Kits include: meter, battery and factory calibration certificate **
Maximum Pressure
Part #
Pricing $US
Range: 0-1.0 in H2O, 0-0.249 kPa 5 psi (0.75 bar)
Range: 0-4.0 in H2O, 0-0.996 kPa 5 psi (0.75 bar)
Range: 0-10 in H2O, 0-2.491 kPa 5 psi (0.75 bar)
Range: 0-20 in H2O, 0-5 kPa 10 psi (0.75 bar)
Range: 0-40 in H2O, 0-10 kPa 10 psi (0.75 bar)
Range: 0-200 in H2O, 0-50 kPa 30 psi (1.99 bar)
Range: 0-10 psi, 0-70 kPa 30 psi (3.99 bar)
Range: 0-20 psi, 0-200 kPa 60 psi (3.99 bar)
Range: 0-30 psi, 0-700 kPa 60 psi (10.3 bar)
Range: 0-100 psi, 0-1000 kPa 150 psi (10.3 bar)
Range: 0-150 psi, 0-1000 kPa 200 psi (10.3 bar)
Optional:  Soft nylon carrying case
(7-1/2" x 3" x 2-1/4")
A-402A 41.75
** To add NIST traceable calibration certificate add -NIST to the part number and $109.00 to the price

Model 477AV - Air Velocity Kit (See ranges above)
477AV-000T-AV   $624.00
477AV-00T-AV   $603.00
477AV-0T-AV   $603.00
477AV-1T-AV   $603.00
Kit Includes:

   * Model 477AV Digital Manometer Selected
   * Model 166T, 36" telescoping stainless steel Pitot Tube
     (Adjustable from 11.5" to 36")
   * (2) No. A-303 static pressure tips with magnetic mounting
   * (2) 4-1/2 ft. lengths 3/16" ID 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
   * Fitted Polyethylene Case

   * Normally stocked

Dwyer Model 477-1T-FM-AV Air Velocity Kit
Dwyer Model 477 Air Velocity Kit

Note: January 2016 pricing subject to change without notice

Dwyer 477AV Manometer Technical Data

Display 0.42" (10.6 mm) 4-digit LCD
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)
Ranges See instrument lising in above table
Pressure Hysteresis ±0.1% of full scale
Units of Velocity fpm, fps, mph, m/h, m/s, k/h, knot
Units of Flow cfm, m3/h, m3/s.
Units of Pressure in w.c., ft. w.c., in Hg, psi, oz/inē, mm w.c., cm w.c., mm Hg, mbar, Pa, kPa, hPa.
Measuring medium Air and compatible gases
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)
Battery type 9 volt
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

Note: These are not FM approved intrinsically safe

Dwyer 477AV Model Chart and Flow Ranges


Dwyer 477AV Manometer Accessory List

Part Number
$US Pricing

A-402A Nylon Carrying Pouch


Nylon carrying pouch 7-1/2" x 3" x 2-1/4".

Dwyer Model 166T telescoping pitot tube166T

The Model 166T Telescoping Pitot tube is a unique air flow sensor which can quickly and easily be adjusted for any duct insertion length from 11.5 to 36 inches (29.2 to 91.4 cm). Now, this single compact unit can replace up to five conventional fixed length Pitot tubes. For even greater convenience, it is securely protected by a custom fitted polyethylene carrying case. Telescoping sections lock in place as they are extended, enabling use of the handle grip to gauge proper alignment of the tip within the airstream. Stainless steel construction resists corrosion. Hemispherical tip has 1.0 flow coefficient, is 1/8" dia. (3.2 mm). Largest section is 3/8" (9.5 mm). Weight (with case) 1 lb, 9 oz (709 g). Case: 12.5 x 6.25 x 1.75 in.
160-8 Pitot tube, 5/16" dia., 8-5/8" insertion length. stainless steel
160-12 Pitot tube, 5/16" dia., 12-5/8" insertion length. stainless steel
160-18 Pitot tube, 5/16" dia., 18-5/8" insertion length. stainless steel
160-24 Pitot tube, 5/16" dia., 24-5/8" insertion length. stainless steel
160-36 Pitot tube, 5/16" dia., 36-5/8" insertion length. stainless steel
160-48 Pitot tube, 5/16" dia., 48-5/8" insertion length. stainless steel
160-60 Pitot tube, 5/16" dia., 60-5/8" insertion length. stainless steel
A-201 Rubber latex tubing has less tendency to kink in storage & occupies less space, thus is best for portable work, 3/16" ID, 9 ft length.
A-202 Rubber latex tubing, 3/16" ID, lengths to 50 ft, per ft.
0.90 per ft

Series 160S type "S" pitot tubes designed specifically for flow measurement of dirty, particulate laden air or gas streams typical in smoke stack and other environmental testing are also available. Large 5/16" dia. Stainless steel tubing resists plugging under harsh, sooty conditions which quickly block conventional flow sensors. Total and static pressure tubes are precisely aligned and welded together every six inches for maximum accuracy, strength and long term durability. Versatile 1/8" female NPT connections easily adapt to any type of pipe or tubing. A pair of 1/8" NPT to 3/16" I.D. tubing adapters is included plus a handy molded vinyl cap to protect tip when not in use. Available in 18, 24, 36, 48, 60 and 72" lengths. Pricing ranges from $169.00 to $2529.00
Pricing effective January 2016, subject to change without notice

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