BPP Bell Piston Prover

Flow calibration with air at gauge pressure

The Bell Piston Prover is a primary standard for flow calibration
with air and other gases (optional) at operating pressure up to 6 bar gauge
pressure (7 bar abs.). The BPP is a calibration standard for sonic nozzles, mass flow meters, LFEs, venturi nozzles and gas meters.

Technical data

BPP2000 – Primary standard 2000 l/h

Measurement range2…2000 l/h
Measurement uncertainty
(30…1000 l/h)		Type A: ≤ 0.08% (k=2)
Type B: ≤ 0.15% (k=2)
Measurement timet > 20
Operating pressureup to 6 bar gauge pressure
(7 bar abs.)
MediumAtmospheric air
Compressed air
Optional: other gases

BPP10.000 – Primary standard 10.000 l/h

Measurement range10…10,000 l/h
Measurement uncertainty
(150…5000 l/h)		Type A: ≤ 0.08% (k=2)
Type B: ≤ 0.15% (k=2)
Measurement timet > 20s
Operating pressureup to 6 bar gauge pressure
(7 bar abs.)
MediumAtmospheric air
Compressed air
Optional: other gases

Measuring principle

The piston is moved via an electrical motor: In the initial state the bell piston is fully retracted (upper position). At the end of a calibration procedure the bell piston is fully extended (lower position). Using the diameter and the travel speed of the piston the flow is determined exactly. The typical measuring time is bigger than 20 seconds. The two pressure chambers are separated by seals and coupled via a switching valve. A bypass is opened with this valve, so that the system with the test piece can be tempered by a pre-set flow rate for any time.

Features

  • Measurement uncertainty up to 0.08% (k=2)
  • Calibration of test items with compressed air and other gases (optional)
  • No measurement errors caused by temperature stratification
  • Fully adjustable air flow
  • Highest accuracy using plunger-piston: Machining and calibration of outside-diameter
  • User defined pre-tempering with bypass
  • No leakage over sealing by using patented plunger-piston

If you have any questions, please do not hesitate to contact our EP-E service team.

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