The detection accuracy of helium mass spectrometer leak detector is crucial, as it directly affects the accuracy and efficiency of detection. However, there are many factors that can affect the detection accuracy of helium mass spectrometer leak detectors, and the following are some of the main factors:
Firstly, due to the influence of testing pressure, different workpieces have varying sensitivities to testing pressure. Generally speaking, for parts with high porosity, the impact of test pressure on leakage rate is greater, while for parts with low porosity, the impact is relatively small. In addition, with the increase of testing pressure, it will also bring many other problems, such as temperature changes and long required stabilization time. Therefore, we suggest conducting leak detection within a certain pressure range for specific workpieces, and then selecting a lower pressure that meets the testing requirements as the final testing pressure. At the same time, the selection of leak testing pressure for the leak testing machine must fully consider the bearing capacity of each mechanism of the tested part for the maximum test pressure.
Secondly, due to the influence of the detection volume, if the detection volume increases, the corresponding pressure reduction rate will be slower, which requires longer time to complete the measurement. In some specific cases, if the measurement volume cannot be reduced, the required accuracy and sensitivity may not be achieved.
Thirdly, the impact of stabilization time on detection is also an important factor. During the inflation process, compressed air entering a sealed container will cause a series of thermodynamic and kinetic changes. When a certain volume of compressed air is rapidly moved to a closed container, its pressure will decrease. When measuring at this time, this pressure change will be considered as a pressure change caused by leakage, which will affect the accuracy of the measurement results. This' inflation effect 'is influenced by inflation pressure, test volume, and test piece material. When the inflation pressure or test volume increases, the pressure decrease caused by inflation becomes apparent. One solution to this problem is to add a stabilization period between inflation and measurement to eliminate this effect.
Finally, temperature also has a significant impact on detection. For gases in sealed containers, as the temperature increases, the internal pressure also increases. Therefore, temperature changes are an important factor affecting pressure changes. It is generally estimated that every 1 ℃ change in temperature will cause a pressure change of 0.36% of the measured pressure value. Therefore, as the testing pressure increases, the influence of temperature will become more pronounced.
In the process of using a helium mass spectrometer leak detector, if we can pay attention to the four influencing factors and related details mentioned above, our detection work will be more efficient and the detection results will be more accurate. The helium mass spectrometer leak detector is an advanced multi-purpose and highly reliable leak detector in the industry, suitable for airtightness testing in various fields.
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