Calories (20°C)
Abbreviation/Symbol:
cal20
Unit of:
Energy
Power
Worldwide use:
As part of the metric system but not an SI unit, calories still have widespread use but are being superceded by the Joule
Definition:
One Calorie (20°C) is the amount of energy needed to raise the temperature of 1 gram of air-free water from 19.5 to 20.5 °C at atmospheric pressure.
Origin:
The calorie was initially defined in 1824 by Nicolas Clément as a unit of heat. It is a metric unit but its use has been superceeded in the SI units by the Joule
Usage context:
As part of the metric system but not an SI unit, calories still have widespread use but are being superceded by the Joule