The calibration procedure for trace sulfur analyzers in high-purity hydrogen usually includes the following steps and requirements:
1. Preparation before verification
Equipment inspection: Ensure that the analyzer is in good working condition and all instruments and accessories are functioning properly.
Environmental conditions: Temperature and humidity should meet standard requirements, and the laboratory should have a stable power supply.
Gas preparation: Prepare high-purity hydrogen gas and a gas standard source containing known concentrations of trace sulfur.
2. Calibration standard gas
Use sulfur standard gas (such as sulfur dioxide or hydrogen sulfide) for analyzer calibration.
The calibration gas concentration should have high accuracy, usually using national standards or certified gas standards.
3. Performance testing of analyzer
Baseline stability test: Confirm whether the baseline of the analyzer is stable under a hydrogen gas flow without sulfur.
Sensitivity check: Using a known concentration of sulfur standard gas, detect it through an analyzer to determine if its responsiveness meets the standard.
Detection limit (LOD) and quantification limit (LOQ): Conduct testing on low concentration sulfur gas to confirm that the instrument can accurately measure the concentration of trace sulfur.
4. Accuracy and precision verification
Accuracy verification: Confirm the repeatability of the analyzer by repeatedly testing standard gases of the same concentration multiple times.
Accuracy verification: Compare with a standard gas of known concentration to calculate the error in the analysis results.
5. Response time and stability
Check the response time of the analyzer (i.e. the time required from gas injection to stable reading).
Record the stability of the analyzer under long-term continuous operation to ensure no drift or error.
6. Calibration and adjustment
Adjust the analyzer according to the calibration results to ensure that its output results are within the allowable error range.
If significant deviations are found, it may be necessary to recalibrate or adjust the sensors and electronic components.
7. Report generation
After the verification is completed, a detailed report should be issued, which should include:
Instrument model, manufacturer, calibration method, and information on the standard gas used.
The results, testing standards, and requirements for each testing project.
Conclusion and recommendations on whether or not to pass.
8. Periodic inspection and maintenance
Regularly conduct calibration and verification to ensure the long-term stable operation of the equipment. Usually calibrated annually or based on frequency of use.
9. Special attention
During the verification process, it is necessary to avoid any sources of pollution (such as impurity gases) that may affect the results.
Standard operating procedures must be strictly followed to avoid human error or instrument damage.
This regulation helps ensure the accuracy and reliability of trace sulfur analyzers in high-purity hydrogen gas during use, and meets relevant standard requirements.