Greyline TTFM 6.1 Transit Time Flow Meter

Accurate Flow Measurement of Clean Liquids with Non-Contacting Transducers

Accurately measure the flow rate of relatively clean, non-aerated liquids like potable water, raw water, cooling water, de-ionized or reverse-osmosis water, oils and chemicals in full pipes. Ultrasonic transducers mount on the outside of a pipe without shutting down flow. Flow rate is displayed on the large, backlit display, along with total volume, signal strength, relay status, and other diagnostic values. Use the built-in control relays as flow alarms or volume totalization. Connect the isolated 4-20mA output to PLC's or controllers. A 128MB data logger is standard, capable of capturing up to 26 million data points. Optional MODBUS RTU via RS-485 available for connection to automation systems.

The TTFM 6.1 works on a wide range of pipe sizes and materials including carbon steel, stainless steel, ductile iron, concrete lined ductile iron, cast iron, PVC, PVDF, fiberglass, copper, brass, aluminum and pipes with bonded liners including epoxy, rubber and Teflon.

The TTFM 6.1 Transit Time Flow Meter operates by measuring the “transit time” or “time of flight” for ultrasonic sound pulses transmitted from one transducer to another. Depending on the mounting configuration, the signal may cross the pipe once, twice or four times. To measure flow the transit time is compared between ultrasonic signals travelling upstream and downstream.

Greyline TTFM 6.1 Features

  • Enhanced Performance
  • Wide Range of Applications
  • Easy to Install and Configure
  • Non-Contacting Clamp-on Ultrasonic Transducers
  • Works on a Large Variety of Pipe Materials and Sizes
  • Large Backlit Flow Rate Display and Totalizer
  • Isolated 4-20mA Output
  • 2 Programmable Control Relays
  • Optional MODBUS® RTU or HART Output
  • Application Optimization Available
  • 128MB Data Logger

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TTFM 6.1 Sales CatalogueTTFM 6.1 User Manual

MicroFlow liquid flow velocity case studies


  • Treated Water
  • Raw Water
  • Cooling Water
  • Low-Conductivity Water
  • Water/Glycol Solutions
  • Hydraulic Oil Diesel & Fuel Oils
  • Chemicals
Product Photos

TTFM Sensor on 6 inch steel pipe

TTFM sensors on a 6" steel pipe.