Thermal equilibrium exists
It is characterized by a universal temperature
Within a system thermal equilibrium is formed
Two systems in thermal contact will exchange heat energy
This exchange process allows for temperature measurement with a thermometer
This exchange process is transitive; i.e. if a system is in thermal equilibrium with two
other systems, both systems are in thermal equilibrium with each other (
Temperature measurements can e.g. be performed with a gas thermometer: For an ideal gas in thermal contact with another system one can e.g. measure the volume; applying the formula
| (1.1) |
this defines the temperature of the gas.
But: the heat exchange can disturb the measured system
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© J. Carstensen (Stat. Meth.)