calorimeters play a key role in heat detection in many industries. Mastering their correct use can ensure the accuracy of test results. Here is a detailed process for using calorimeters.

Preparation before use

Before use, make sure that the calorimeter is placed on a stable, dry and free of strong electromagnetic interference. Check the appearance of the instrument to confirm that the components are firmly connected and not loose or damaged. At the same time, prepare the sample to be tested. The sample must meet the shape and quality requirements specified by the instrument. For example, the solid sample should be ground evenly, and the liquid sample should be uniform and free of precipitation. In addition, the matching auxiliary supplies such as ignition wire and oxygen cylinder should be prepared, and the oxygen purity should meet the specified standards.

Instrument calibration

Calibration is the core step to ensure the accuracy of the measurement of the calorimeter. Turn on the instrument and let it preheat for a period of time. After the instrument is stable, select the standard material for calibration according to the instrument manual. Common standard materials include benzoic acid. Press an appropriate amount of benzoic acid into pieces, put it in a burning dish, and operate according to the calibration procedure set by the instrument. During the calibration process, closely observe the various parameters of the instrument to ensure that the calibration results meet the requirements. If the calibration results deviate greatly, it is necessary to re-check the instrument status and calibration steps until the calibration is qualified.

sample testing

Put the processed sample into the burning dish, install the ignition wire, and ensure that the ignition wire is in good contact with the sample. Close the oxygen bomb cover of the calorimeter and tighten the seal to prevent oxygen leakage. Fill the oxygen bomb with an appropriate amount of oxygen, and the pressure should reach the specified value of the instrument, generally controlled at 2.8-3.0MPa. Put the oxygen bomb into the inner cylinder of the calorimeter, connect the ignition electrode, and cover the upper cover of the instrument.

Enter the sample quality, relevant parameters and other information on the instrument operation interface to start the test program. The instrument will automatically complete the ignition, heat measurement and other processes. During this period, pay attention to the operation status of the instrument. If there is an abnormal alarm, stop the test immediately to troubleshoot the problem. After the test, the instrument will display the measurement results and record the relevant data.

post-test processing

After the test is completed, wait for the instrument and the oxygen bomb to cool to room temperature, carefully remove the oxygen bomb, open the bleed valve, and slowly release the oxygen to avoid danger caused by sudden pressure drop. Take out the combustion dish, clean the remaining samples and ashes, and clean and maintain the combustion dish, oxygen bomb and other components to keep the instrument tidy. Finally, turn off the power supply of the instrument, organize the experimental supplies, and store the instrument properly.

By mastering the operation process of the calorimeter and strictly following the operating specifications, the heat detection work can be completed efficiently and accurately, providing reliable data support for related work.