Pressure and Velocity Air Balancing Instruments

Magnehelic® Air Velocity Kit

Magnehelic® Air Velocity Kits contain gauge in plastic carrying case, with aluminum stand, two 1/8" NPT to rubber tubing adapters, 9 foot length of 3/16" tubing, and brass terminal tube.

Use with pitot tube (order separately) for air velocity measurement, or without pitot tube for pressure measurement. Magnehelic gauges are less sensitive to level than liquid, yet offer accuracy to ±2% over the full scale. Air Velocity Scale provides direct reading without conversions. They are handy to use on a ladder or in confined locations. Provides exceptionally responsive, consistently accurate indication of air velocity, positive, negative or differential pressures.

Dual Range Air Balancing Kit

Our most popular precision air velocity instrument, the ABK400 is used to balance air conditioning systems, measure drop across filters, test fan and blower discharge and inlet pressure, as well as air velocity in ducts.

  • Measure both pressure and velocity
  • Read the red figures directly in f.p.m.
  • Read the black figures in inches W.C.
  • No conversion tables needed

A versatile, all around manometer for the air conditioning and air balancing contractor or industrial plant engineer.

Complete air velocity meter kit includes:

  • Inclined vertical manometer
  • Stainless steel calibrated pitot tube
  • Air velocity calculator slide rule
  • Two 9 ft. lengths of rubber tubing with connectors
  • Magnetic mounting clips
  • Additional gauge oil
  • Steel carrying case

Air Velocity-Static Pressure Kit

Simplest, quickest to use air velocity instrument we know of. The AVK1000 Air Meter is very popular for service work or air conditioning, heating and ventilating equipment. Direct reading air velocity and static pressure scales — both high and low range — show supply and return grille velocities, duct air velocities, furnace draft, pressure drop across air filters, etc.

A Complete Pocket-Sized Kit!

Includes air meter, return and supply grille probes, angle connector, cleaning materials, instruction card, air velocity calculator, carrying case and one extra plastic ball in plastic tube.

Dwyer Magnehelic Gauges

  • For positive, negative or differential air pressure
  • Flush or surface mounted
  • Wide choice of ranges available

Gauge Connections: 1/8" NPT high and low pressure taps, duplicate one pair side and one pair back. Valves showing are extra.


  1. As an Air Filter Gauge measuring pressure drop across an air filter to indicate when filters need servicing.
  2. Sensing static pressure in an air system.
  3. Measuring air velocity in determining volume of flow.

Other magnehelic gauges are available in PSIG, KPA, and CM of water.

To sense static pressure For the most accurate measure of static pressure in an air stream, use a gauge connected to a static pressure tip such as DWYER Model A-301.

As a gauge to check air filters Gauge gives an instant visual indication when filters need servicing.

To determine flow

To measure air velocity (with optional pitot tube)

Air filter gauge package (A-605) Adapts any standard Magnehelic for use as an air filter gauge. Includes surface-mounting bracket, screws, 10 ft. tubing, two static pressure tips.

Vent Valves (A-310A)
Where pressure is continuous and the magnehelic gauge is connected by tubing which cannot be easily removed.
Gauge includes these mounting accessories:
two 1/8" SPT plugs, two 1/8" NPT to tube adapters, and flush mount adapters with screws.

Part # Range (in. w.c.)  
A-310A Vent Valve Call... Add to Order
A-432 Plastic Carrying Case Call... Add to Order
A-605 Air Filter Kit Call... Add to Order

Handheld Digital Manometer

Measures positive, negative and differential pressure

This lightweight handheld digital manometer accurately fills a variety of monitoring and troubleshooting needs in HVAC systems. The highly accurate (0.01'' w.c.) LCD display gives you a new calibration and setup tool at an attractive price. Use for pressure testing, balancing, VAV setup and clean room needs. A standard 9-volt battery (included) gives you up to 500 operating hours. The large 1/2'' readout is easy to read under most service lighting conditions. Used with a pitot tube.


  • Power: 9-volt battery
  • Connections: 1/8'' or 3/16'' tube
  • Weight: 12 oz. (incl. battery)
  • Accuracy: 0.1% full scale
  • Display: 1/2'' LCD

A-402 Carrying Pouch

Tough gray nylon pouch protects any Series 475 Manometer and includes a convenient side compartment for tubing and other accessories. Both areas are fully zippered for easy access. With belt loop, hand strap and adjustable shoulder strap. 7''x4.5''x3''.

Part # Range Manometer/Accessories  
166-6-CF - 6" Pocket Pitot Tube with Compression Fitting Call... Add to Order

Digital Air Velocity Kit

Convenient all-in-one kit is small, light and easy to use. No setup or leveling needed. Digital manometer reads from 0–19.99'' w.c. Large 1/2'' LCD readout is easy to see in poorly lighted areas and has a “low battery” warning. Included is a 6'' stainless steel pitot tube with integral compression fitting to hold it securely when taking readings. Also, two static pressure tips with magnetic mounting measure pressure drop across filters, condenser coils, etc. An indispensible test kit for the plant engineer, industrial hygienist an HVAC technician.

475-1-AV Air Velocity Kit, includes:
(1) 475-1 Manometer
(2) A-303 static pressure tips
(2) 9 ft. lengths of rubber tubing
(1) 166-6-CF pitot tube
(1) A-397 air drill
(1) A-532 air velocity slide chart
all packed in a tough, molded plastic carrying case with die cut foam liner

Static Pressure Tips

These sensors are used to sense static or differential pressure for duct or building pressure measurement.


  • manometers
  • Magnehelic gauges
  • pneumatic transmitters
  • differential pressure switches
  • low pressure transducers
  • system powered controls
  • VAV controls
  • static pressure switches
Part # Pressure Tip Description  
A-301 1/4" compression connection Call... Add to Order
A-302 3/16" or 1/8" ID barbed connection Call... Add to Order
A-303 Magnet-mount 3/16" ID tube connection Call... Add to Order
A-305 Low resistance tip - 1/8" NPT Call... Add to Order
A-306 Outdoor static pressure sensor with 50' tubing and mounting bracket Call... Add to Order
A-307 Static pressure fitting, 1/4" compression Call... Add to Order
A-308 Static pressure fitting, 1/4" barbed Call... Add to Order

Stainless Steel Pitot Tubes

Pitot tubes differ from static pressure tips. They have two internal tubes that measure static pressure and total pressure. Use with air velocity gauges, balancing kits, pneumatic air velocity transmitters, electronic air velocity transducers, and other applications where air velocity measurement is needed.


  • 304 stainless steel constructionInch graduations on sides of 160 series to quickly determine exact insertion depth
  • Dwyer Air Velocity Calculator, direct reading flow charts and instructions included
  • Use 1/8'' models in ducts as small as 4''; 5/16'' models in ducts 10'' or larger
  • No calibration needed
Part # Description Length  
160-12 Standard - 5/16" 12" Call... Add to Order
160-18 Standard - 5/16" 18" Call... Add to Order
160-24 Standard - 5/16" 24" Call... Add to Order
160-36 Standard - 5/16" 36" Call... Add to Order
160-48 Standard - 5/16" 48" Call... Add to Order
160-60 Standard - 5/16" 60" Call... Add to Order
160-8 Standard - 5/16" 8" Call... Add to Order
166-12 Pocket Size - 1/8" 12" Call... Add to Order
166-6 Pocket Size - 1/8" 6" Call... Add to Order
A-159 Duct Mounting Flange --  Call... Add to Order

Air Measurement Gauge Fluids

Blue Gauge Oil (1.910 – for Mark II models 26 and 28, and other special instruments
Fluorescein Green Color Concentrate 3/4oz.
– water coloring agent contains wetting agent for use in vertical manometers only
Red Gauge Oil
(0.826 – for use in manometers and all Dwyer gauges using red oil
Violet Gauge Oil
(1.000 – use in place of water for better meniscus and visibility

These replacement fluids have been specifically formulated for use in Dwyer and other liquid filled measurement devices. They are designed with high visibility colors and the exact specific gravity ( needed for the listed instruments.

Digital Thermo Anemometer

The Model 471-1 Digital Thermo Anemometer is a versatile dual function instrument which quickly and easily measures air velocity in four field selectable ranges—feet per minute or meters per second—plus air temperature in °F or °C. High contrast LCD display shows both range selected and present velocity. Convenient backlight provides perfect visibility in low light conditions. Low battery warning is included. Extruded aluminum housing protects electronics yet is lightweight and comfortable to hold even when taking multiple readings. Stainless steel probe with comfortable hand grip is etched with insertion depth marks from 0–8 inches and 0–20 cm. An integral sliding cover protects sensors when not in use.


  • Temperature measurement to 200°F
  • ±3% full scale accuracy
  • Four air velocity ranges to 0–15,000 fpm

1 0–500 0–3.0
2 0–1500 0–7.0
3 0–5000 0–30
4 0–15,000 0–70

Part # Thermo Anemometer  
471-1 Digital Thermo Anemometer includes battery, wrist strap, 6-step drill, carrying case and instructions Call... Add to Order

Air Velocity Transmitter

Velocity in – 4 to 20mA out

This Dwyer Air Velocity Transmitter is ideal for a wide range of HVAC measurement and control applications, including:

  • VAV systems
  • Building automation systems
  • Energy management systems
  • Velocity measurement and control.
Power 24Vac/dc
Ranges Field Selectable: 0-200, 0-1000, 0-3000, 0-12,000
Output 4-20mA
Length 12 Sensor 6 Cable
Housing NEMA 13

Part # Air Velocity Transmitter  
640-0 Dwyer Air Velocity Transmitter Call... Add to Order