Engineering Specifications
Portable Ultrasonic Flow Meter
Greyline PTFM 1.0


SCOPE: This specification covers a portable, ultrasonic Transit Time flow meter by Greyline Instruments, Massena, New York / Long Sault, Ontario. This portable instrument shall provide for non-intrusive flow measurement, indication, totalizing and transmitting of the flow rate in a full pipe.


Each portable Transit Time flow meter shall have the following design features and engineering specifications:


  1. The ultrasonic flow meter shall have an accuracy of 1% of reading or 0.1 ft/sec (0.03 m/sec), whichever is greater. Have repeatability and linearity of 0.25%.
  2. Shall operate on clean liquids in full pipes with less than 2% solids or gas bubbles at flow velocities from 0.07 to 39 ft/sec (0.02 to 12 m/sec).
  3. Operate on the following pipe materials: carbon steel, stainless steel, PVC, PVDF, fiberglass, galvanized steel, mild steel, ductile iron, glass, copper, brass and pipes with bonded liners including cement, epoxy, rubber and Teflon.
  4. Operate on AC power or from internal, rechargeable batteries.


  1. The flow meter shall have a dual transmitting/receiving, clamp-on transducers operating at 1.28MHz.
  2. The transducers shall operate continuously at temperatures from -40F to 300F (-40C to 150C).
  3. The standard transducer pair shall be designed to install on pipes with nominal diameter ranging from 1/2" to 48" (12 mm to 1200 mm).
  4. Have 12 ft (3.4 m) length coaxial cables from the electronics with BNC connectors to transducers.
  5. Shall include manufacturer's recommended transducer coupling compound. Shall include stainless steel mounting hardware, pipe clamps and aluminum alignment bar.
  6. Shall include BNC seal jackets for transducer operation in wet or submerged conditions.


  1. Have a portable ABS electronics enclosure with a padded, watertight IP67 carrying case. Total weight shall be less than 15 lbs (7 kg).
  2. Electronics shall be designed for continuous operation at temperatures from -5 to 140F (-20 to 60C).
  3. Have a built-in 5-key calibration keypad with operator selection of parameters through visual prompts from a menu calibration system. Systems requiring calibration by Parameter codes or external calibrators shall not be accepted.
  4. Have user-selectable menu languages including English, French and Spanish.
  5. Have a white, backlit matrix display indicating flow in user-selected engineering units, totalized flow, units of calibration, and signal strength.
  6. Have display backlight brightness adjustment for reduced power consumption.
  7. Have flow proportional 4-20mA output rated to maximum resistive load of 500 ohms.
  8. Have a built-in 300,000 point data logger, USB output and connecting cables. Data logger shall support time and date-stamped logging and generate formatted flow reports including total, average, minimum, maximum and times of occurrence.
  9. Include Windows software for data log retrieval, graphing and export.
  10. Have automatic signal strength and signal confidence monitoring.
  11. Have keypad adjustable minimum flow rate cutoff.
  12. Shall include an external with CE/UL approved charger with 100-240VAC 50/60Hz input.
  13. Shall include an internal NiMH rechargeable battery with minimum capacity for 18 hours continuous battery operation.
  14. Have a battery status indicator with automatic low battery shut off and battery overcharge protection.
  15. Have user-selectable "sleep mode" synchronized to data logger sample rate for reduced battery power consumption.


  1. Include additional 150 g. manufacturer's recommended ultrasonic sensor coupling compound.
  2. Include 50 ft (15 m) length Sensor Cable extension complete with connecting plugs.


The instrument shall be a Model PTFM 1.0 Portable Transit Time Flow Meter as manufactured by Greyline Instruments Inc., and warranted against defects in materials and workmanship for one year.

Specifications are subject to change without notice. 

Please contact Greyline if you need more information or for advice in your application. We can provide quotations and refer you to the Greyline sales representative in your area. (To receive complete information please provide your name, mailing address, phone and fax numbers):

Greyline Instruments Inc.
16456 Sixsmith Drive
Long Sault, Ont. K0C 1P0
Tel: 613-938-8956 / 888-473-9546
Fax: 613-938-4857
Greyline Instruments Inc.
105 Water Street
Massena, NY 13662
Tel: 315-788-9500 / 888-473-9546
Fax: 315-764-0419

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