Answer: calorimeter.
A calorimeter is a device used to measure the absorption or release of heat in chemical and physical processes.
Explanation:
The word calor means heat in latin. So, the technique or science to measure the transfered (absorbed or released) heat in a chemical or physical process is called calorimetry and the apparatus (device) used is named calorimeter.
The physical principle on which this science is based is the conservation of energy or first principle of thermodynamic.
Heat realeased by a component = heat absorbed by other component.