The discussion revolves around identifying reproducible thermal phenomena that can be used for calibrating thermometers, particularly focusing on the boiling and melting points of water and their reliability due to pressure sensitivity.
The discussion is ongoing, with participants raising questions about the nature of phase changes and their pressure sensitivity. Some guidance has been provided regarding the need to specify pressure when using water's phase changes as calibration points, but no consensus has been reached on alternative reproducible phenomena.
Participants reference slides that suggest using reproducible thermal phenomena for calibration, indicating a potential constraint in understanding the definitions and implications of these phenomena in different contexts.
I don't know, they said in the slides that to calibrate a thermometer we should place it in reproducible thermal phenomena.Bystander said:What sorts of phenomena do you think would be useful?
I don't know. I'm lost now. Then they mean by reproducible phenomena phases like steam point and melting point?Bystander said:What phase changes are not pressure sensitive? Are you familiar with "the phase rule?"
okay thanks a lotBystander said:https://www.physicsforums.com/threads/is-the-definition-of-a-phase-arbitrary.891651/#post-5609568
Follow along here, if you will, and things will become clear as mud.
The boiling point and freezing point of water are basic 'fixed points' in defining the Celsius temp scale. You are correct to state that these depend on pressure so the pressure must also be specifiedAny Help said:I don't know, they said in the slides that to calibrate a thermometer we should place it in reproducible thermal phenomena.
So what are those reproducible phenomena? do they mean boiling and melting point of water?
if they mean boiling and melting of water, as we know water is pressure sensitive so its not reliable from place to place? so how to calibrate thermometer with that? it won't be precise.