In this video by the team at Cal State University in San Bernadino, the students walk through the proper instructions of how flow meter calibration works. As a note the gas flow calibration should be done first before any liquid calibration is done. Also included in the demonstration is the software that is used to provide the most accurate readings and compare past calibrations. Flow meter calibration is necessary before starting any project.
For more about flow meter calibration visit the CSUSB Human Performance Lab HERE