Vermes
Advanced Member level 4
It is a microprocessor based meter of volume and gas flow built with the principle of a syringe driven by a stepper motor and gas to and from the syringe is directed by a three-way valve.
The key element is differential pressure sensor that detects an increase in pressure at the inlet system and it is a signal for the microcontroller to pull out the piston.
When the entire syringe is filled, SW limit switch detects this condition, then the microcontroller switches the valve and blows the gas.
The measuring element is the incremental encoder, whose signal increments the variable volume of the gas.
The measurements can be read on the operator panel with alphanumerical display 4x20. There is also a keyboard to navigate through the menu, RS-232 connector and signal LEDs.
PCBs are noteworthy. It is a little hard to fit everything in a free version of Eagle, but it is possible to make in dual-layer technology.
Link to original thread (useful attachment) – Mikroprocesorowy miernik ilości i przepływu gazu