calorimeter

A bomb calorimeter is used to measure the energy that is given out when one mole of a substance is completely burned in oxygen. A known amount of the substance is placed in the crucible, oxygen is added at 20 atmospheres pressure, and then the substance is ignited using the heated wire. As the calorimeter heats, it heats the water. The rise in water temperature is measured and from this the heat generated by the burning substance is calculated.

Instrument used in physics to measure various thermal properties, such as heat capacity or the heat produced by fuel. A simple calorimeter consists of a heavy copper vessel that is polished (to reduce heat losses by radiation) and covered with insulating material (to reduce losses by convection and conduction).

In a typical experiment, such as to measure the heat capacity of a piece of metal, the calorimeter is filled with water, whose temperature rise is measured using a thermometer when a known mass of the heated metal is immersed in it. Chemists use a bomb calorimeter (so called from its sturdy pressure-resistant casing, which somewhat resembles the casing of a bomb) to measure the heat produced by burning a fuel completely in oxygen.