Editing Operational definition (section)

=== Temperature ===
The thermodynamic definition of [[temperature]], due to [[Nicolas Léonard Sadi Carnot]], refers to heat "flowing" between "infinite reservoirs". This is all highly abstract and unsuited for the day-to-day world of science and trade. In order to make the idea concrete, temperature is defined in terms of operations with the gas thermometer. However, these are sophisticated and delicate instruments, only adapted to the national standardization laboratory.

For day-to-day use, the [[International Temperature Scale of 1990]] (ITS) is used, defining temperature in terms of characteristics of the several specific sensor types required to cover the full range. One such is the [[electrical resistance]] of a [[thermistor]], with specified construction, [[calibration|calibrated]] against operationally defined fixed points.