First, the basic preparation before the calorimeter

Before adjusting the calorimeter, it is necessary to do a good job of equipment inspection and environmental preparation. Confirm that the appearance of the calorimeter is not damaged, the power supply connection is stable, and the heat dissipation port is not blocked. At the same time, ensure that the temperature and humidity of the laboratory are stable, avoid direct sunlight or strong air interference, and lay a solid foundation for accurate debugging. In addition, prepare standard benzoic acid, ignition wire, oxygen cylinder and other calibration consumables, and the consumables must meet the equipment adaptation standards to prevent the mismatch of consumables from affecting the debugging accuracy.

II. Detailed explanation of the core calibration steps

1. Heat capacity calibration: This is the core link of the calorimeter. First turn on the power supply of the calorimeter to preheat for 15-20 minutes. After the equipment is stable, weigh an appropriate amount of standard benzoic acid, wrap it tightly and put it into the oxygen bomb, connect the ignition wire and ensure good contact. Fill the oxygen bomb with oxygen to the specified pressure, put the oxygen bomb into the inner cylinder of the calorimeter, and start the calibration procedure. After the equipment automatically completes the combustion and temperature measurement processes, record the heat capacity data. If the data deviation exceeds the allowable range, it needs to be recalibrated until it reaches the standard.

2. Temperature calibration: The temperature accuracy of the calorimeter directly affects the test results. Enter the equipment calibration mode, use a qualified thermometer, and compare the temperature displayed by the calorimeter with the actual temperature. If there is any deviation, follow the equipment manual and fine-tune the parameters through the calibration interface until the displayed temperature is consistent with the actual temperature to ensure the accuracy and reliability of the temperature measurement system.

III. Key parameter setting and debugging

After the calibration is completed, key parameters need to be set according to the characteristics of the test sample. Mainly include ignition time, stirring speed, water volume in the inner cylinder, etc. The ignition time needs to ensure that the sample is fully burned, generally set to 1-2 seconds; the stirring speed needs to be uniform and stable to avoid affecting the water temperature measurement; the water volume in the inner cylinder needs to be added in strict accordance with the requirements of the equipment manual. Too much or too little will lead to heat transfer deviation and affect the accuracy of the test results. After the setting is completed, a blank test can be carried out, and the parameters can be fine-tuned according to the test results

IV. Post-commissioning verification and maintenance

After the debugging is completed, the effect needs to be verified by the actual sample testing. Select a standard sample with known calorific value for testing, and compare the test results with the standard value. If the error is within the allowable range, it means that the debugging is successful. If the error exceeds the standard, it is necessary to re-check the calibration steps and parameter settings, and check the ignition wire connection, oxygen pressure and other details. Daily equipment maintenance is also required. Regular cleaning of oxygen bombs and inner cylinders is required to check the line connection to ensure the long-term stable operation of the calorimeter and ensure the detection accuracy.