Using A Prover - Allen-Bradley 1756-CFM User Manual

Using a Prover

A prover is used for the calibration of liquid meters in custody transfer
applications. This calibration is done by comparing a metered throughput to a
known volume in the prover. When enabled, the prover total updates while the
spheroid moves between two detectors and is then compared to the
predetermined volume of the prover section to ascertain the meter factor.
If you are using the Totalizer or Nonresettable Totalizer mode for capturing
meter counts during a prover calibration, you have the option of selecting
either of these types of provers:
• Unidirectional - With a unidirectional prover, the module:
- begins updating Prover Total when the spheroid passes the first
detector
- stops updating Prover Total when the spheroid passes the second
detector
• Bidirectional - With a bidirectional prover, the module:
- begins updating Prover Total when the spheroid passes the first
detector
- stops counting when the spheroid passes the second detector (Prover
Total is updated at this time - intermediate value returned)
- continues updating when the spheroid returns past the second
detector
- stops updating when the spheroid returns past the first detector
(Prover Total Count Value is updated at this time)
This figure shows an example of a spheroid and detectors.
Rockwell Automation Publication 1756-UM010C-EN-P - June 2021
Chapter 3 Configurable Flowmeter Module Features and Operational Modes
Detectors
Spheroid
37