In all kinds of experiments and production scenarios involving heat measurement, calorimeters play a crucial role, and the accuracy of their measurement results directly affects the reliability of experimental data and product quality. In order to ensure that the calorimeter can always operate accurately, regular calibration is essential. Below, we will introduce the calibration method of calorimeters in detail.

Preparation before calibration

Before calibrating, it is necessary to ensure that the appearance of the calorimeter is intact, free of damage and stains. At the same time, prepare standard materials, such as benzoic acid, whose calorific value is known and stable, which is an ideal choice for calibrating the calorimeter. In addition, auxiliary equipment such as ignition wires and oxygen cylinders need to be prepared, and to ensure that the oxygen purity meets the requirements. The ambient temperature and humidity also need to be kept stable to avoid environmental factors interfering with the calibration results.

Instrument installation and inspection

Install the components of the calorimeter correctly, check whether the inner cylinder, outer cylinder and other components are installed in place to ensure that there is no loosening. Turn on the power supply of the calorimeter, preheat for a period of time, and check whether the functions of the instrument are normal, such as the ignition system, temperature sensor, etc. If any abnormalities are found, they need to be checked and repaired in time to ensure that the instrument is in the best working condition.

Reference material weighing and filling

Use a high-precision balance to accurately weigh the reference material and record its quality. Put the weighed reference material into the crucible and connect the ignition wire to ensure that the ignition wire is in good contact with the reference material. Then put the crucible into the oxygen bomb of the calorimeter, taking care to avoid the standard material spilling during the operation. After the filling is completed, fill the oxygen bomb with an appropriate amount of oxygen and fill it with oxygen according to the specified pressure to ensure that the oxygen bomb is well sealed.

Calibration procedure

Put the oxygen bomb filled with the standard material into the inner cylinder of the calorimeter and close the lid of the instrument. Enter the calorific value, quality and other relevant information of the standard material on the operation interface of the instrument to start the calibration procedure. The instrument will automatically perform operations such as ignition and measurement of temperature changes, and record the temperature data during the whole process. After the measurement is completed, the instrument will calculate the actual calorific value according to the measurement data and compare it with the known calorific value of the standard material.

Data logging and analysis

Record all the data during the calibration process in detail, including the quality of the reference material, temperature change, actual calorific value, etc. Calculate the error of the calorimeter by comparing the actual calorific value with the standard calorific value. If the error is within the allowable range, the calibration is qualified; if the error exceeds the allowable range, the calorimeter needs to be adjusted, such as adjusting the instrument parameters, checking the sensor, etc., and then re-calibrated until the error meets the requirements.

post-calibration maintenance

After the calibration is completed, clean the calorimeter to remove dust and stains from the surface of the instrument. Maintain the instrument regularly, check the wear and tear of each part, and replace the damaged parts in time. At the same time, establish a calibration file to record the time and results of each calibration for subsequent inquiry and traceability.

Mastering the calibration method of the calorimeter can not only ensure the accuracy of the measurement results, but also prolong the service life of the instrument. By strictly following the above steps for calibration, the calorimeter can always maintain the best performance and provide reliable data support for experiments and production.