A calorimeter is a detector which fully absorbs the particles. The particle initiates a particle shower. Calorimetry is the science of measuring the heat exchange between a system and its surroundings to calculate the change in energy of the system. A calorie is the amount of energy required to raise one gram of water by 1 degree C (1 kelvin). The ease of measurement of energy. One technique we can use to measure the amount of heat involved in a chemical or physical process is known as calorimetry.