How to design an automated system to measure flow rate of a gas
(bubble ) ..and thus able to calliberate the mass flow controller.
There are many types of electronic gas flowmeters. They measure either the pressure drop through a venturi, or the head caused by a pitot tube, or the rpm of a rotor, or the time-difference of the acoustic waves travelling up and down stream, or the change of reistance of a hot wire, or the bias across a flexible piezo element, and many other schemes.
We understand that we need a section discussing transducers, sensors and detectors and we do plan on doing so in our future revisions. Until then, if you would like to tell us what is the type of the flowmeter you are using, we can probably write a few paragraphs explaining how that particular type works.