The Core Principle of Calorific Value Calibration of calorimeter

The core of calorimeter calorific value calibration is to rely on the law of conservation of thermodynamic energy to accurately calibrate the heat measurement system of the instrument through the reference material with known calorific value to ensure the accuracy of subsequent detection data. The essence of calibration is to establish the corresponding relationship between the indicated value of the instrument and the real calorific value, eliminate the interference caused by the error of the instrument itself and the ambient temperature difference, and build a solid data foundation for the calorific value detection of coal, fuel and other samples.

Required preparations before calibration

1. Standard material screening: Preference is given to the nationally certified standard benzoic acid, which has a stable calorific value and meets the purity standard. At the same time, auxiliary materials such as ignition wire and oxygen are prepared to ensure that the reagents meet the calibration requirements.

2. Instrument status check: carefully check the sealing of the oxygen bomb of the calorimeter to avoid incomplete combustion due to air leakage; confirm that the water temperature of the inner and outer cylinders is stable, and the various components of the instrument are operating normally without cards or malfunctions.

3. Control of environmental conditions: Calibration should be carried out in a constant temperature environment, with room temperature fluctuations controlled within ± 1 ° C, and direct light and air flow interference should be avoided to reduce the impact of environmental factors on the calibration results.

Standardized calibration operation steps

1. Standard material weighing: accurately weigh 0.9-1 g standard benzoic acid with a high-precision balance, press it into a sheet, and firmly fix it on the ignition wire in the oxygen bomb to ensure good contact.

2. Oxygen bomb assembly and oxygenation: Fill the assembled oxygen bomb with sufficient oxygen, control the pressure at 2.8-3 MPa, let it stand for 1 minute, confirm that there is no air leakage, and put it into the inner cylinder of the calorimeter.

3. Program calibration operation: Start the calibration program, enter the accurate calorific value of standard benzoic acid, and the instrument automatically completes the ignition, heat collection, and calculation. Repeat the calibration 3-5 times, and take the average value after excluding the data with excessive deviation.

4. Results verification adjustment: The calibrated instrument is tested on the standard sample with known calorific value. If the result deviates from the standard value within the allowable range, the calibration is qualified; if the deviation exceeds the standard, the instrument status needs to be re-checked and calibrated again.

Key Considerations for Calibration

1. Standard material storage: Standard benzoic acid should be sealed and stored in a dry and cool place to avoid moisture and deterioration. It should be fully dried before use to ensure stable calorific value.

2. Control of operation specifications: Weighing, assembling oxygen bombs and other links need to be strictly operated according to the process to avoid human errors; oxygenation pressure and time need to be accurately controlled to ensure that the sample is fully burned.

3. Regular calibration and maintenance: After the instrument is used for a long time or key components are replaced, it needs to be re-calibrated in time; a calibration ledger needs to be established daily to record the calibration time and results to ensure that the instrument is always in an accurate state.

By standardizing the calibration process and strictly controlling the details of each link, the calorimeter calorific value detection data can be ensured to be accurate and reliable, providing solid technical support for fuel quality determination and energy accounting.