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  • UFM-1



  • For clean water with <3% by volume of particulate content
  • Range:0.33 to 32.8 ft/s (0.1 to 10 m/s)
  • Accuracy: ±3% of flow reading for > 0.98 ft/s (> 0.3 m/s)
  • Backlit display
  • Outputs:
    • Analog: 1 opto-isolated: 4 to 20 mA
    • Pulse: 1 opto-isolated MOSFET relay
  • IP54 rated enclosure
  • Repeatability: ±0.5% of measured value
  • Response Time: < 1 s
  • CE approved
  • Compatible with steel copper or plastic pipes
  • Pipe Outside Diameter: 0.98 to 4.62" (24.89 to 117.35 mm)
  • Pipe Wall Thickness: 0.02 to 0.39" (0.5 to 10 mm)

What's in the Box

  • Converter w/ adjustable guiderail
  • Set of 1.81 to 2.75” (46 to 70 mm) clamps
  • Set of 2 to 5” (51 to 127 mm) clamps
  • Set of small pipe adaptor circle clamps
  • Set of small pipe adaptor V clamps
  • Ultrasonic coupling grease


The Dwyer UFM Compact Ultrasonic Flowmeter is a low cost clamp-on, ultrasonic flowmeter. The Model UFM implements the transit-time difference to measure flow rates in pipes non-invasively. It is a compact and lightweight design, featuring an easily installed, all in one clamp-on unit. This unit can measure velocity and flow in pipes with outside diameters ranging from 0.98 to 4.62" (24.89 to 117.35 mm). The screen offers easy to read text with a convenient backlight for visual comfort. This model comes with a volume pulse and 4 to 20 mA flow rate output.

Principles of Operation

Two sensors located in the guiderail are placed on the exterior of the pipe, and each transmits an ultrasonic pulse through the pipe and fluid to the other. The velocity of the liquid flowing through the pipes causes the pulse to accelerate or decelerate. The difference in the transit times of the two pulses is used to calculate the flow rate. The use of transit time allows the flowmeter to be unaffected by pressure or temperature changes.

Product Applications

  • Flow measurement for heat metering
  • Process water metering and monitoring
  • Chilled water metering and monitoring
  • Clean water, no bubbles
  • Potable water metering and monitoring


This product can be used in the following applications: