Greyline Instruments PDFM 5.1 User Manual (English)

Questions and Answers:

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Randy EvansAug 2, 2025
Why is my Greyline Instruments Measuring Instruments meter reading too high?
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  William WatkinsAug 2, 2025
  A meter reading that's too high can stem from several causes: * **Calibration error:** Review the UNITS/MODE menu and Pipe ID. * **Vibration or noise:** Try installing the device in another location. * **Pipe not full:** Remount the sensor on a vertical pipe. * **Nearby velocity increasing device:** Relocate the sensor more than 30 pipe diameters away from the device. * **Variable Speed Drive interference:** Adhere to the drive manufacturer's wiring and grounding instructions, and relocate the flowmeter, sensor, and wiring away from the VSD.
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Lisa PorterAug 6, 2025
What to do if Greyline Instruments Measuring Instruments meter reading is lower than expected?
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  Michael BrownAug 6, 2025
  A lower-than-expected meter reading can be due to several reasons: * **Calibration Error:** Review the UNITS/MODE menu and Pipe ID. * **Lower flow rate:** Investigate the pump/valves and compare the velocity with an alternate instrument. * **Signal penetration:** Relocate the sensor closer to elbows or flow disturbances. * **Improper sensor mounting:** Reinstall the sensor with careful application of coupling compound. * **Pipe not full:** Remount the sensor on a vertical pipe.
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eharrisonAug 11, 2025
What causes erratic readings on my Greyline Instruments Measuring Instruments?
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  Donald BrownAug 11, 2025
  Erratic meter readings can occur if the sensor is mounted too close to a valve, pump, or elbow. To resolve this, change the sensor placement. It's recommended to position it 6-10 pipe diameters from elbows and 30 pipe diameters from pumps, controlling valves, orifice plates, nozzles, or open pipe discharge.
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Yvette KhanAug 17, 2025
Why Greyline Instruments Measuring Instruments shows reading when there is no flow?
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  khillAug 17, 2025
  If your meter is showing a reading when there is no flow, consider these possibilities: * **Vibration on pipe:** Adjust the Status / Signal Cutoff setting or install in another location. * **Variable Speed Drive interference:** Follow the drive manufacturer's wiring and grounding instructions. Relocate the flowmeter, sensor, and wiring away from the VSD. * **Incorrect sensor connections:** Refer to the connections diagram.

Greyline Instruments PDFM 5.1 Specifications

General

Type	Portable Doppler Flow Meter
Operating Temperature	-20 to 60°C
Temperature Range	-20 to 60°C
Electronics Enclosure	NEMA 4X (IP66)
Sensor Material	Stainless Steel
Application	Flow measurement in full pipes
Velocity Range	0.03 to 12.2 m/s
Pipe Size Range	12.5 mm to 4.5 m
Output	4-20 mA, RS232
Power Supply	12-24 VDC
Process Connections	Clamp-on
Display	LCD