how electronics fuel dispenser works

[sohaib_a]

I have tried to search online alot on this but couldn't get a definitive explanation.So I'm hoping someone here can help me out.

I have to control the fuel flow from a computer.After a certain amount (in liters) is filled the pump should stop or when the tank is full.I read some articles on how flow measurement control happens in a fuel dispenser.A turbine is used along with a rotary shaft encoder.Is this correct?I get the turbine part, it rotates as the fuel flows but what does this rotary shaft encoder do?And how does the pump stop automatically?

It would've been easier if I could get my hands on fuel dispenser but unfortunately I cant.So i am hoping someone here who has can tell me something about it?

 

[Hero999]

I'm no expert but I'm sure you could build once from parts of an old car. A fuel pump and flow meter are the two main components you need.

I don't think this sounds like a very safe project, all the components need to be safe to use in an explosive atmosphere which means it should be all solid state, no relays or switches.

 

[duffy]

The rotary shaft encoder spins a "chopper wheel"
**broken link removed**

that breaks the beam of an opto. (take apart an old ball-type mouse, there's 2 of them in there)

The processor counts the pulses, flow is proportional to the speed.