Use of a bomb calorimeter can also be described as a constant-volume calorimeter measuring the heat of combustion / calorific value of a particular reaction under standard conditions. Bomb calorimeters are designed to endure and sustain large pressure inside the calorimeter chamber as the reaction has to be measured simultaneously. The fuel is ignited with the help of electrical energy during the process in which fuel is burning, it simultaneously heats up the surrounding air. This hot air expands and passes through a ventilation copper tube that directs the air out of the calorimeter. Now during this process when the air is passing through this copper ventilation tube it will also heat up the water outside the tube via convection. Now, the calorie content of the fuel / sample is calculated by the change in temperature of the water.