Hi, I am very new to refrigeration (Just passed exams) I am wandering could anyone tell me where I can find a comparitor (think that's what their called it is tipping it down and I dont feel like getting very wet going out to the van to get my notes and be sure) I mean the slide rule thing for showing type of gas, pressure and temp.
I am looking for a computer based one that I can use on my PC and just to be a posh git on my PDA, hopefully a free one,

Many thanks

Peter