First, the basic preparation before the adjustment of the calorimeter

Before adjusting the calorimeter, it is necessary to ensure that the equipment is in a stable operating state. First check whether the power connection of the calorimeter is normal to ensure the voltage is stable and avoid affecting the performance of the equipment due to voltage fluctuations. At the same time, clean the outer surface and key components of the calorimeter to prevent dust and impurities from interfering with the measurement accuracy. In addition, prepare standard materials, such as benzoic acid with known calorific value, which is an important basis for subsequent calibration and adjustment.

Second, the adjustment of key parameters of the calorimeter

1. Temperature parameter adjustment

The core function of the calorimeter is to accurately measure heat, and temperature control is crucial. Enter the parameter setting interface of the device and set the appropriate temperature range according to the experimental needs. Generally speaking, the working temperature of the calorimeter needs to be kept in a relatively stable range. By adjusting the temperature control system of the device, the deviation between the actual temperature and the set temperature can be controlled within the allowable range. If the temperature fluctuates greatly, it is necessary to check whether the heating element and temperature sensor are normal, and repair or replace them in time.

2. Stirring speed adjustment

The mixing system can ensure that the sample fully reacts and the heat is transferred evenly. When adjusting the stirring speed, it needs to be carried out according to the nature of the sample and the experimental requirements. For samples that are easy to react, the stirring speed can be appropriately increased to ensure that the reaction is sufficient; for samples with slow reaction, it is necessary to reduce the stirring speed to avoid heat loss due to excessive stirring. By observing the rotation of the stirring paddle, adjust it to a suitable speed to ensure the stability and accuracy of the experiment.

III. Calibration and adjustment of the calorimeter

1. Calibration with reference materials

Put the reference material with known calorific value (such as benzoic acid) into the oxygen bomb of the calorimeter, and carry out ignition measurement according to the operation process. After the measurement is completed, compare the actual measured value with the theoretical calorific value of the reference material. If there is any deviation, the heat capacity of the calorimeter needs to be adjusted according to the calibration procedure of the equipment. By adjusting the calibration coefficient, the measurement results are consistent with the theoretical value to ensure the measurement accuracy of the calorimeter.

2. Oxygen bomb pressure adjustment

The oxygen bomb is a key component of the calorimeter, and its pressure directly affects the combustion effect of the sample. Before each experiment, the pressure of the oxygen bomb needs to be checked, generally between 2.8 and 3.0MPa. If the pressure is insufficient, a special inflatable equipment needs to be used to make up the pressure; if the pressure is too high, some gas needs to be released to ensure that the pressure is within the specified range. At the same time, check the tightness of the oxygen bomb to prevent oxygen leakage and affect the experimental results.

IV. Verification and precautions after adjustment

After the adjustment of the calorimeter is completed, a verification experiment needs to be carried out. Multiple measurements are made using samples with different calorific values to observe the stability and accuracy of the measurement results. If the deviation of multiple measurements is small, it means that the adjustment is successful; if the deviation is large, the adjustment steps need to be re-checked to find the problem. In addition, during the adjustment process, it is necessary to strictly follow the operation manual of the equipment to avoid damage to the equipment due to improper operation. At the same time, regular maintenance of the calorimeter is carried out to ensure that the equipment is always in good operating condition.