What is the Difference Between Adiabatic and Isoperibol Calorimeter?

The main difference between adiabatic and isoperibol calorimeters lies in the temperature control of their environments. Here are the key differences between the two types of calorimeters:

• Adiabatic Calorimeter: In an adiabatic calorimeter, the environment is controlled so that no energy is lost or gained. The calorimeter vessel (bomb vessel) and bucket are surrounded by a water jacket, which is strictly heated and cooled to maintain the same temperature as the inner bucket. The temperature in the jacket (Tov) is kept the same as the temperature inside the vessel (Tiv) throughout the test, achieving a reasonably "perfect insulation". No correction calculations are required for adiabatic calorimeters.
• Isoperibol Calorimeter: In an isoperibol calorimeter, the temperature in the jacket (Tov) is kept constant throughout the test. The surrounding water jacket is controlled to be at a constant temperature. A correction factor (Regnault-Pfaundler = ξ) that takes the heat flow into account is calculated after the test. Isoperibol calorimeters are also known as isothermal calorimeters.

In summary, adiabatic calorimeters maintain a constant temperature in both the jacket and the vessel, while isoperibol calorimeters keep the jacket temperature constant. Both types of calorimeters are used for various applications, and the choice between them depends on the specific requirements of the experiment or measurement.

Comparative Table: Adiabatic vs Isoperibol Calorimeter

The main difference between adiabatic and isoperibol calorimeters lies in their boundary conditions and the mode of operation. Here is a table comparing the two types of calorimeters:

In summary, adiabatic calorimeters are used for measuring runaway reactions and require a correction factor for heat loss, while isoperibol calorimeters are used for routine and occasional measurements and involve heat exchange with the surroundings.