To determine the heat capacity of bomb calorimeters benzoic acid is used, as a standard, because it is obtained in pure form and its energy of combustion is accurate.
So, what causes the benzoic acid to read below average?
This can have many reasons as follows:
- You could be experiencing leaking within the bomb vessel.
- If you have changed consumables without calibration for your calorimeter system.
- Lack of calibration.
- Oxygen not filling to recommended 30 bar of oxygen pressure using the Filling Station.
- The quality of oxygen you are using is of a poor quality.
- The quality of the benzoic acid tablets you are using.
Conclusion:
For accurate readings on Benzoic Acid be sure to check your vessel for any leaks, check all O-rings for leaks and make sure regular maintenance on the vessel lid assembly and O-rings is followed. Calibrate your bomb calorimeter system on regular intervals during the day.
Use a good quality high pressure oxygen regulator to fill the vessel with the required pressure. Make sure you use good quality Industrial oxygen of 99.9% purity.
Store your Benzoic Acid in a cool, dry place, always store in the original container with the cap tightly closed.
