Starting at $2,695.00

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  • Works on metal and plastic pipes
  • Flow velocity of ±0.07 to 39ft/sec typical
  • 2 to 48 inch pipe diameter
  • ±1% of reading or 0.1ft/sec accuracy
  • ±0.25% repeatability & linearity
  • 26 million point data logger standard
  • NEMA4X (IP 66) polycarbonate case
    • Water & dust tight with clear, shatterproof cover
  • Large backlit flow rate display and totalizer
  • Isolated 4-20mA/0-5V output
  • Built-in 5-Key calibrator
  • Optional Modbus RTU via RS-485
  • Control Relays:
    • 2 programmable control relays standard
    • 4 additional relays optionally available

The Greyline Instruments TTFM 6.1 ultrasonic flow meter is a simple, non-contact, transit time flow meter for use with clean, non-aerated liquids like water, chemicals, and oils in full pipes. Since the ultrasonic transducers mount on the outside of pipes, the TTFM 6.1 has no obstruction to flow and no pressure drop. Additionally, this makes for easy installation and doesn't require the system be shut down. No contact is made with the moving fluid and no pipe cutting or drilling is required. There is no fouling or scale build-up on the sensor.

The Greyline TTFM 6.1 works on a wide range of pipe materials including carbon steel, stainless steel, ductile iron, cast iron, PVC, PVDF, fiberglass, copper, brass, aluminum and pipes with bonded liners including epoxy, rubber and Teflon. The non-intrusive, clamp-on ultrasonic sensor fits any pipe with an inside diameter from 2 to 48 inches. Display and totalize flow in your choice of engineering units (gallons, liters etc.). The TTFM 6.1 transit time flow meter includes an isolated 4-20mA to transmit flow to remote displays, recorders or controllers. The two programmable relays (upgradeable to six) can be used for flow control, flow alarms or flow proportionate pulse.

Calibration of the Greyline Instruments TTFM 6.1 ultrasonic flow meter is easy with the built-in 5-key calibrator. The standard sensor is rated non-incendive for Class I, Division II hazardous locations and the TTFM 6.1 can be equipped with optional Intrinsic Safety Barriers for sensor installation in Class I, Division I hazardous locations. A built-in 26 million point data logger with USB output to flash drives is included standard. A Modbus RTU via RS-485 is available as an optional upgrade for wireless communication.


Greyline Instruments Transducer Cables
Replacement pair of triaxial cables with BNC connectors and seal jackets
Greyline Instruments DXC Sensor Cable
RG174U shielded coaxial pair available in lengths up to 500 feet


Greyline Instruments SE16B Ultrasonic Transducer
Single clamp-on transit time ultrasonic transducer (two are required for use)


Please consider these optional accessories.

Greyline Instruments CC Coupling Compound
Acoustic couplant is gel applied to the sensor face to ensure a complete acoustic pathway between the sensor and the pipe wall
Greyline Instruments JB4X Cable Junction Box
NEMA4X/IP66 polycarbonate junction box for extending cable lengths of dual sensor installations
Greyline Instruments CHS Spare Electronics Set
Spare set electronics with mounting chassis (standard features)
Part Number Price Available
TTFM 6.1-A-1-A-1-B-2-A-2-A
Show Configuration
Base Price
Power Input
Standard, 100-240VAC 50/60Hz
Standard NEMA4X (IP66) polycarbonate
Enclosure Temperature
Standard (-5° to 140°F / -20° to 60°C)
Intrinsic Safety
Standard - SE16B Transducers (No Hazardous Area Rating)
Transducer Mounting Hardware
TMK-B21 (TMK-B1 + alignment ruler for 2 to 6 in. pipes) (+$125.00)
Transducers Cables
25ft pair coaxial with BNC connectors and seal jackets
Serial Communications
Modbus RTU via RS-485 (+$240.00)
Control Relays
2 standard relays, rated 5 amp SPDT, programmable
$3,060.00 1

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