1、 Calibration standards

Calibration environment: The dynamic chemical adsorption instrument should be placed in an environment with stable temperature and suitable humidity to avoid moisture or temperature fluctuations affecting its performance.

Calibration steps:

Instrument preparation: Check whether all components of the instrument are intact, ensure that the gas pipeline is unobstructed, and that the valves and flow controllers are working properly.

Standard substance calibration: Use standard substances with known characteristics (such as standard gases or standard samples) for calibration. Set experimental parameters according to the instrument operation manual and collect measurement data under different conditions.

Data processing: Compare the collected data with the standard values of reference materials, calculate the instrument's indication error and repeatability.

Calibration result evaluation: Based on the calibration results, determine whether the instrument meets relevant standards and requirements. If it does not meet the requirements, the instrument needs to be adjusted or repaired.

Calibration cycle: It is recommended to conduct regular calibration, and the calibration cycle can be determined based on the instrument usage and calibration results, generally not exceeding one year.

2、 Measurement uncertainty analysis

Sources of uncertainty: Measurement uncertainty mainly comes from factors such as instrument readings (including repeatability and resolution), standard values of reference materials, measurement environment, measurement personnel, and measurement methods.

Uncertainty assessment:

A-class evaluation: Uncertainty is evaluated by statistical analysis of the repeatability of measurement data, such as using the Bessel formula to calculate experimental standard deviation.

B-class evaluation: Evaluate uncertainty based on experience or other information, such as purity uncertainty indicated on standard substance certificates, repeatability and linear error of balance weighing, etc.

Composite standard uncertainty: Combine the uncertainty components obtained from Class A and Class B evaluations to obtain the total uncertainty.

Uncertainty report: The uncertainty report should include detailed information such as measurement results, uncertainty values, sources of uncertainty, and evaluation methods, so that users can understand the reliability and accuracy of the measurement results.