I am learning experimental physics and I am covering mass spectrometers and multiwire proportional counters. Anyway I have been trying to find out what temperature these are kept at while these are in operation. For instance gas filled mass spectrometers usually use helium to get an average charge state for the recoiling ions passing through them. This I understand, but I have not read anywhere what temperature the helium is kept at, I only see the pressure. Likewise for the MWPC, I read that compounds such as Isobutane can be used and its pressure is given, but I never see the temperature that it is kept. Am I to assume that they are both kept at room temperature for operation ? The density is never given either so I can't use this to determine the temperature. Any know what temperature these are kept at ?