Assistance with a seemingly strange pirani gauge

I'm working on a vacuum system and so far things have gone unusually well for my projects and I really hope to keep doing well on it, but I'm hung up on the vacuum gauges. I've got a PR10-S Edwards Pirani gauge and the internal circuitry is strange. I can't find any literature on it anywhere or any schematics close enough to fudge. So I'm hoping I'blers might have a clue as to what is going on here. EDIT: Added a re-drawn circuit in an estimated configuration After some googling, a 3-wire resistance thermometer seems close to what I have as thats essentially what the gauge is, a clever application of a resistance thermometer.

Question by The Ideanator 7 years ago  |  last reply 7 years ago


Schematic symbols?

I found this schematic in a 1947 manual on vacuum systems and I cant translate the indicated DPDT switch into something I understand. Can anyone sketch a quick pinout for it, preferably indicating what goes where on the schematic. This goes along with my other pirani gauge question.

Question by The Ideanator 7 years ago  |  last reply 7 years ago