Primary water flow calibration to 0.1% repeatability error

Precision Calibration water flow rig

Frank designed and built this 1800 litre water calibration flow rig in its entirety.

It is designed to calibrate the measurement accuracy of flowmeters, in particular impeller turbine flowmeters.

The rig has less than 0.1% measurement repeatability error. Such a small error is considered very good and can be considered a “primary” measurement calibration flow rig

Then he tasked his students to program the system and to measure the output of the turbine flow meter multiple times to see its repeatablity error and thus to deduce a measurement calibration coefficient (litres/turbine pulse).

Frank also taught his students how to design and build the turbine flowmeter.

This included the manufacture of the turbine

impeller on a manual milling machine.

Frank also designed a stepper motor controlled valve in the top tank that control the water flow. The stepper motor drove a stainless steel leadscrew and it turned out that the valve system was so repeatable that its opening aperture size could be used to control accurately the flow rate.