First, preparations before adjustment

Before using a calorimeter for testing, making basic preparations is the premise of accurate adjustment. First, ensure that the calorimeter is placed in a stable, dry and non-strong electromagnetic interference environment to avoid environmental factors affecting the instrument. Second, check whether the power connection of the instrument is stable. After turning on the power supply, let the instrument warm up for at least 30 minutes. After the various parameters of the instrument are stable, the follow-up operation will be carried out. At the same time, prepare the standard sample. The calorific value of the standard sample needs to be accurately known, which is the key basis for subsequent calibration adjustment.

II. Initial adjustment of key parameters

The core parameter adjustment of the calorimeter directly affects the accuracy of the test results, focusing on the two parameters of temperature and oxygen bomb pressure. For temperature adjustment, enter the parameter setting interface of the instrument, and set the appropriate starting temperature and target temperature range according to the characteristics of the test sample. Generally, the starting temperature can be set between 20 ° C and 25 ° C, and the target temperature needs to meet the temperature change requirements of the sample after complete combustion. Oxygen bomb pressure adjustment is also critical. Use a special oxygen bomb pressure adjustment device to adjust the pressure in the oxygen bomb to 3.0MPa-3.2MPa. Too high or too low pressure will lead to insufficient sample combustion, which will affect the detection results.

Third, the calibration operation realizes accurate adjustment

Calibration is the core part of the adjustment of the calorimeter, and the system error of the instrument can be eliminated by calibration. Put the prepared standard sample into the oxygen bomb, add an appropriate amount of distilled water, and complete the ignition and detection according to the operation process of the instrument. After the test is completed, record the measured calorific value displayed by the instrument and compare it with the known calorific value of the standard sample. If there is a deviation between the two, enter the calibration interface of the instrument and enter the calibration coefficient according to the deviation value. Generally, if the deviation is small, the calibration coefficient can be fine-tuned according to the proportion of the deviation. After the calibration is completed, re-test with the standard sample again until the error between the measured calorific value and the standard calorific value is controlled within the allowable range, usually the error

Fourth, daily maintenance to ensure the adjustment effect

The long-term accurate adjustment of the calorimeter is inseparable from daily maintenance. After each use, it is necessary to clean the residue on the inner wall of the oxygen bomb in time to keep the oxygen bomb clean and avoid the residue affecting the follow-up inspection. Regularly check the key components such as the sensor and heating device of the instrument to ensure that the performance of the components is good. At the same time, a comprehensive calibration re-inspection is carried out at least once a month to correct the possible parameter drift of the instrument in time to ensure that the calorimeter always maintains an accurate adjustment state and provides a reliable guarantee for the detection work.