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Model 641B Air Velocity Transmitter

Brand: Dwyer Instruments, LLC
Does not ship to United States
The Model 641B Air Velocity Transmitter uses a heated mass flow sensor suitable for dirty air flow applications.

A Low-Cost, Direct Reading Instrument Used for Both Air Velocity & Static Pressure Tests.

It has user-selectable ranges from 250 FPM (1.25 MPS) to 2000 FPM (10 MPS).
Features
  • SS Sensor Suitable for Dirty Air Flow Measurement
  • Ranges from 250 FPM (1.25 MPS) to 2,000 FPM (10 MPS)
  • 4 to 20 mA Output
  • Digital Filter for Signal Damping
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The Model 641B Air Velocity Transmitter uses a heated mass flow sensor suitable for dirty air flow applications.

A Low-Cost, Direct Reading Instrument Used for Both Air Velocity & Static Pressure Tests.

It has user-selectable ranges from 250 FPM (1.25 MPS) to 2000 FPM (10 MPS).
Features
  • SS Sensor Suitable for Dirty Air Flow Measurement
  • Ranges from 250 FPM (1.25 MPS) to 2,000 FPM (10 MPS)
  • 4 to 20 mA Output
  • Digital Filter for Signal Damping

Specifications

Accuracy

  • 5 % of Full Scale Process Gas: 0° to 50° C (32° to 122° F)
  • 6 % Full Process Gas: -40° to 0° C & 50° to 80° C (-40° to 32° F & 122° to 176° F)

Ambient Temperature Range

  • 0° to 60° C (32° to 140° F)

Consumption

  • 300 mA - Max.

Electrical Connectors

  • Screw Terminal

Environmental Protection

  • IP66
  • NEMA 4X

Loop Resistance

  • 600 ohms, Max.

Media

  • Compatible Air
  • Non-Combustible Gases

NPT Connection

  • 1/2” NPT Female
  • 1/2” NPT Male

Output

  • 4-20 mA Isolated 24 V Source, 3 or 4-Wire Connection

Power Requirement

  • 10-16 Vac
  • 12-35 Vdc

Process Temperature

  • -40° to 80° C (-40° to 176° F)

Response Time

  • 0.5 to 15 seconds
  • 1.5 seconds to 95 % of Final Value

Typical Applications

  • Exhaust stack flow monitoring
  • Air control in drying processes
  • HVAC air velocity measurements
  • Fan supply and exhaust tracking
  • Clean room ventilation monitoring