GB/T 44007-2024 in English

3.1 Instrument selection and calibration

According to the requirements of the standard, a physical adsorption instrument that meets the technical indicators of GB/T44007 should be selected. Pay special attention to the following points:

• Analytical balance: The graduation value is 0.1 mg to ensure accurate sample weighing.
• Physical adsorption instrument: vacuum degree not less than 1 Pa, pressure sensor accuracy ±0.15%.
• It is recommended to calibrate the instrument performance regularly, especially the pressure and temperature sensors.

3.2 Sample pretreatment and degassing

The sample needs to be fully degassed before measurement. The specific steps are as follows:

1. Determine the degassing temperature of the sample, which can be determined by thermogravimetric analysis or experimental method.
2. Degas under vacuum conditions, with a vacuum degree of about 1 Pa or less.
3. After degassing, it needs to be quickly cooled to room temperature to avoid secondary adsorption.

3.3 Data processing and uncertainty analysis

The calculation of hydrogen storage capacity involves multiple parameters, and key data should be accurately recorded:

• Hydrogen compressibility factor Z: It is recommended to refer to the NIST standard database or use the Virial equation for calculation.
• Sources of measurement uncertainty include factors such as balance accuracy, pressure sensor error and temperature fluctuation.
• It is recommended to use certified standard samples to verify the results to improve data reliability.

3.4 Experimental report writing specifications

A complete experimental report should include:

• Basic information of the experiment: equipment model, operator, test date, etc.
• Sample information: detailed description of source, chemical composition, purity, etc.
• Measurement conditions: temperature, pressure range and specific parameter settings.
• Data recording and analysis results: hydrogen storage calculation process and verification method.