When I was managing the hydraulic system business for a major manufacturer we had a contract to supply hydraulic power units for machine tools. One day we had a problem with a power pack that showed low flow during test. We went through a fault finding exercise:
- Check the motor speed
- Check the motor coupling
- Check the pump, in fact we changed the pump
- Made sure there were no restrictions in the pipework
After we checked the above we were puzzled as to what was causing the problem. We only had one analogue flow meter, like the one in the picture. We had a flowmeter that connected to a data logger and tried it. The flow from the hydraulic power unit was as expected so the problem was with the analogue flowmeter.
What did we do? We purchased another two flowmeters and calibrated them on a test rig and disposed of the damaged flow meter. We then had a flowmeter to compare the other against and a check on both every 3 months.
It is important your equipment for testing does not give you false results.
