Evacuating a sample of unknown fluid (to vaporize for mass spectrometry). Pressure drop causes a decrease in temperature. The fluid simultaneously both boils and freezes? Would like some insight here... Edit: Thanks for the help guys. It appears we have found the triple point of the substance! Edit2: The substance is Cyclohexane! To use this video in a commercial player or in broadcasts, please email This email address is being protected from spambots. You need JavaScript enabled to view it.