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Dwyer

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Product Image of 3-Way Plastic Vent Valve 1/8" NPT to 1/4" Metal Tubing
$44.93 each
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Product Image of Large Diaphragm Pressure Switch w/ Visual Set Point Adjustment (.05" - .25" W.C.)
$569.99 each
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Product Image of Aluminum Surface Mounting Plate for Magnehelic Gage
$32.18 each
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Product Image of Solid Core Current Switch (5-50A)
Solid Core Current Switch (5-50A)
SKU: MCS-111050
Dwyer
SKU: MCS-111050
Brand: Dwyer
$29.41 each
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Product Image of Straight Stainless Steel Pitot Tube (48" Insertion Length)
$489.88 each
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Product Image of Flotect Brass Explosion-Proof SPDT Liquid Level Switch w/ External Float Chamber
$581.14 each
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Product Image of Differential Pressure Transmitter, 4-20 mA (0 - 1.0" W.C.)
$164.42 each
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Product Image of 1/16 DIN Temperature/Process Controller, Current Output 1 & Relay Output 2 (100 to 240 VAC)
$171.96 each
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Product Image of 1/2" NPT Flotect Explosion-Proof Mini-Size Brass SPDT Flow Switch w/ Brass Tee
$400.64 each
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Product Image of Differential Pressure Transmitter, 4-20 mA (0 - 2" W.C.), w/ Selectable 0 to 10 / 0 to 5V Output
$138.29 each
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Product Image of Flotect Universal Vane-Operated Brass Flow Switch
$910.55 each
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Product Image of Aluminum Mounting Flange w/ Gasket & Screws for 1/8" Tubing
$25.11 each
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Product Image of Compact Low Differential Pressure Switch (4.0" - 20.0" W.C.)
$93.27 each
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Product Image of Analog Signal Generator w/ LED Bar Graph & Carrying Case
$357.61 each
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Product Image of Static Pressure Tip, Stainless Steel w/ Mounting Flange for 3/16" Tubing (8" Insertion)
$20.89 each
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Product Image of Handheld Digital Manometer (0 - 200" W.C.)
Handheld Digital Manometer (0 - 200" W.C.)
SKU: 475-3-FM
Dwyer
SKU: 475-3-FM
Brand: Dwyer
$315.09 each
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Product Image of Digital Temperature Switch (24 VAC/VDC)
Digital Temperature Switch (24 VAC/VDC)
SKU: TS2-040
Dwyer
SKU: TS2-040
Brand: Dwyer
$69.55 each
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Product Image of Side Wall Mount Liquid Level Switch, 304 Stainless Steel Cylindrical Float
$411.56 each
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Product Image of Magnesense Differential Pressure Transmitter, Wall Mount w/ LCD, (.15", .25", .5" W.C.)
$202.53 each
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Product Image of Gas Pressure Kit w/ Slack Tube Manometer
Gas Pressure Kit w/ Slack Tube Manometer
SKU: 1212-DWYER
Dwyer
SKU: 1212-DWYER
Brand: Dwyer
$274.48 each
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Product Image of Flotect Brass Explosion-Proof SPDT Liquid Level Switch, Spherical Side Wall Mount
$451.12 each
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Product Image of Stainless Steel Pitot Tube (5/16" Dia., 24-5/8" Insertion Length)
$156.40 each
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Product Image of Brass Adapter, 1/8" NPT to 3/16" Rubber and 1/8" ID Plastic Tubing
$8.08 each
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Product Image of Stainless Steel Pitot Tube (5/16" Dia., 12-5/8" Insertion Length)
$138.57 each
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Product Image of 3/4" NPT Flotect Explosion-Proof Mini-Size Brass SPDT Flow Switch w/ Brass Tee
$362.59 each
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Product Image of CO2 Transmitter, Duct Mount, 2000 PPM Range, 4-20 mA / 0-5/10 VDC
$259.91 each
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Product Image of Timer Controller (10 Channels)
Timer Controller (10 Channels)
SKU: DCT610
Dwyer
SKU: DCT610
Brand: Dwyer
$284.28 each
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Product Image of Photohelic Pressure Switch Gage (0 - 10" W.C.)
$713.35 each
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Product Image of Aluminum Stand-Hang Bracket for Magnehelic Gage
$36.99 each
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Product Image of Explosion-Proof Paddle Level Switch (115 VAC)
Explosion-Proof Paddle Level Switch (115 VAC)
SKU: PLS2-E-1-1
Dwyer
SKU: PLS2-E-1-1
Brand: Dwyer
$380.37 each
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Product Image of Low Differential Pressure Switch, SPDT (.3" - 1.0" W.C.)
$148.66 each
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Product Image of 1-1/4" NPT Flotect Explosion-Proof Mini-Size Brass DPDT Flow Switch w/ Brass Tee
$637.57 each
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Product Image of Low Differential Pressure Switch, DPDT, Manual Reset (2.5" - 9.0" W.C.)
$274.96 each
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Product Image of 1/2" NPT Low-Flow Flotect Explosion-Proof Mini-Size Brass SPDT Flow Switch, w/ Brass Tee
$379.52 each
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Product Image of Solid Core Current Switch (Fixed 0.50A, N.O., LED)
Solid Core Current Switch (Fixed 0.50A, N.O., LED)
SKU: CCS-121050
Dwyer
SKU: CCS-121050
Brand: Dwyer
$24.49 each
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Product Image of Pocket Pitot Tube (1/8" Dia., 12" Insertion Length, 1-1/2" Tip)
$156.35 each
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Product Image of Split Core Current Switch (N.O.)
Split Core Current Switch (N.O.)
SKU: CCS-231150
Dwyer
SKU: CCS-231150
Brand: Dwyer
$37.11 each
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Product Image of Differential Pressure Transmitter, 4-20 mA (0 - 40.0" W.C.)
$287.77 each
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Product Image of Low Cost Timer Controller (10 Channels)
Low Cost Timer Controller (10 Channels)
SKU: DCT510A
Dwyer
SKU: DCT510A
Brand: Dwyer
$263.82 each
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Product Image of Explosion-Proof Heavy-Duty SPDT Thermostat (36-Degree to 82-Degree (F))
$680.16 each
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Product Image of 2000 Series Differential Pressure Gauge (0 - 20" W.C.)
$91.27 each
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Product Image of Wet/Wet Differential Pressure Transmitter, 4-20 mA (0 to 50 PSID)
Wet/Wet Differential Pressure Transmitter, 4-20 mA (0 to 50 PSID)
SKU: 629C-04-CH-P2-E5-S1
Dwyer
SKU: 629C-04-CH-P2-E5-S1
Brand: Dwyer
$636.58 each
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Product Image of Digital Differential Manometer (+/-60" W.C.)
$236.17 each
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Product Image of Pressure Snubber (316 Stainless Steel, 1/4" MNPT x FNPT)
$39.39 each
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Product Image of Flotect Brass Magnetic Float Switch, Side Wall Mounting
$862.09 each
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Product Image of Explosion-Proof Differential Pressure Switch (3.0" - 11.0" W.C.)
$382.13 each
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Product Image of 7-21/32" Averaging Flow Sensor
7-21/32" Averaging Flow Sensor
SKU: PAFS-1004
Dwyer
SKU: PAFS-1004
Brand: Dwyer
$20.06 each
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Product Image of Straight Stainless Steel Pitot Tube (18" Insertion Length)
$296.83 each
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More About Dwyer

Dwyer Instruments traces its roots to 1931, when the F.W. Dwyer Manufacturing Company was founded in Chicago to produce liquid filled manometer test instruments. In 1953 the company developed the Magnehelic gauge, which grew into its flagship product and helped drive the company's expansion.

As the business grew, Dwyer moved its headquarters from Chicago to Michigan City, Indiana, where it remains today, with additional offices supporting customers across Asia, Europe, and Australia. The company now manufactures instrumentation for HVAC and process automation markets.

Product Lines

Dwyer's pressure product line includes the Series 2000 Magnehelic differential pressure gauges and Series MSX Magnesense differential pressure transmitters, both used to measure low air or non-corrosive gas pressure. The catalog also covers manometers, flow meters, flow switches, and flow indicators for measuring flow rate in liquids and gases.

Beyond pressure and flow, Dwyer supplies controllers, data loggers, remote displays, and sensors for temperature, level, and air velocity, along with calibration services and accessories for the instruments it manufactures.

Why Contractors Specify Dwyer

Magnehelic gauges have been used in the field since the 1950s for tasks like filter monitoring, duct static pressure checks, and cleanroom pressure differential readings, giving contractors a design with a long track record. Because the gauge uses a frictionless internal movement, it reads pressure without external power.

Carrying pressure, flow, level, and temperature instruments under a single brand simplifies sourcing replacement parts and matching new installations to existing equipment already in the field. That range makes Dwyer instruments a common choice for HVAC balancing, air quality monitoring, and process control work.

How to Choose Dwyer Products

Begin with what needs to be measured: pressure, flow, level, or temperature, since Dwyer's product lines are organized around these measurement types. For pressure applications, decide between a mechanical gauge like the Series 2000 Magnehelic for local visual readings or a transmitter like the Series MSX Magnesense when a signal needs to reach a building automation or control system.

Check the pressure range, accuracy, and gas compatibility required for the application, and confirm whether the instrument will be exposed to corrosive gases before selecting a model. Mounting location and available power at the install point should also factor into the choice between a gauge and a transmitter.

Frequently Asked Questions

What is a Magnehelic gauge used for?

It measures low differential air or non-corrosive gas pressure, whether positive, negative, or differential, and is commonly used for filter monitoring, duct static pressure, and cleanroom pressure differential readings.

What is the difference between the Series 2000 Magnehelic gauge and the Series MSX Magnesense transmitter?

The Series 2000 is a mechanical dial gauge for local visual reading, while the Series MSX is an electronic transmitter that sends a signal to a building automation or control system.

Does a Magnehelic gauge need external power?

No, the Magnehelic gauge uses a frictionless internal movement and does not require external power to operate.

Where is Dwyer Instruments headquartered?

Dwyer is headquartered in Michigan City, Indiana, with additional offices in Asia, Europe, and Australia.

What industries rely on Dwyer instrumentation?

Dwyer instruments are used in HVAC and process automation applications, including air quality, flow, level, temperature, and process control monitoring.