Do you know what the "negative leakage" in the air tightness tester test result means?

During routine airtightness testing work, the有时候我们会遇到Airtightness Tester显示负值的情况，我们可能时常会在测试报告中见到「负泄漏」这样一个词汇。For many novice operators, they see those three words and raise an eyebrow, thinking something is wrong with the test results. In reality.「负泄漏」只是leak detector在特定情况下会显示的正常值，并不意味着测试失败。

I still remember that when I saw the word "negative leakage" in the report for the first time, I was also confused. As a new technician of JCGK, I was not very skillful with all the test data, and when I saw "negative leakage", which I had never seen before, I wondered if I had done something wrong, for fear of affecting the quality of the product. Now, as a testing engineer with some experience in the industry, I would like toWith this article, I'd like to share a tip for my peers in the industry - look positively at the common term 'negative leakage' in test report forms.

Ⅰ.Reasons for negative values

此类情况一般常见于使用差压气密测试仪测试的案例当中，注意有以下几个原因引起：

a) Leakage of the standard part, the standard part is used to compare the pressure with the inspected part during the differential pressure test to analyze whether there is leakage or not, if the standard part is leaking, it will lead to the pressure of the inspected part being greater than that of the standard part, and at this time, the instrument will show the result of a negative leakage value.

b) Standard parts are subjected to external environmental factors different from those of the test parts, such as temperature and environment, which result in a drop in pressure, thus presenting a negative indication of leakage.

c) The structural residual candle or volume difference between the standard part and the tested part is too large, thus causing the pressure change characteristics of the tested part to be inconsistent with that of the tested part, resulting in a negative display or an abnormal leakage value display.

Ⅱ.prescription

针对Airtightness Tester出现负值的问题，我们可以考虑以下解决方案：

a) Leakage problems with standardized parts

• The standards can be tested individually to rule out their own problems. If the standard behaves normally, you can continue to the next step.
• If there is a problem with the standard, it needs to be replaced with a new standard for testing.

(b) Standardized parts are subject to different external environmental factors than tested parts

• Control the environmental conditions of the standard parts and test parts in the testing process. For example, keep both at the same temperature for testing to minimize the effect of external temperature differences.
• Multiple tests can also be averaged to minimize random errors.

c) Excessive structural residual candles or volume differences between the standardized parts and the inspected parts

Check the consistency of the standardized parts with the tested parts in terms of physical structure, etc.. For example, whether the unit size is the same, whether the complexity of the structure is balanced, etc.

III.give an example

在使用 JC-C10005 Differential Pressure Airtightness Tester时，作为对比基准的水冷板标准品状态也可能导致最终的负泄漏结果。这是因为差压检测仪的原理是通过比较测试端与基准端的压力差异来判定测试品的气密性The

Differential Pressure Airtightness Tester，水冷板测试结果出现负的泄漏值

If the standard itself fails and leaks, and the sealing of the test article is better than that of the standard that fails and leaks, the results will be inverted.--The test article appears to "seal better" than the standard article, resulting in a reverse negative leakage result.

There are several countermeasures against this negative leakage induced by standards:

• Replace standard leakage products regularly to prevent their quality from decaying too rapidly;
• Check the condition of the standard before each test to avoid its malfunction and leakage;
• Prioritize an assay structure with dual standards benchmarking against each other to reduce the single-point risk of standard failure;
• Establishment of perfect management of standardized products to avoid their damage caused by human factors.

The correct state of the standard is critical to the accuracy of the differential pressure test.We hope that these contents can help you further understand and guard against the problem of standards in differential pressure testing, so as to improve the accuracy of airtightness testing.

IV. Summary

不论是在消费电子行业、新能源汽车制造还是其他领域，Airtightness Tester都扮演着重要的角色。通过了解负值出现的原因和解决方案，我们可以更好地理解和应对这一现象。

Through this article, I believe you will have a better understanding of the words 'negative leakage'.In our work, we should give maximum respect to each test result, and we should not draw any conclusions. Only by comprehensively analyzing the test data and making comprehensive judgments with reference to the product characteristics can we give reliable test conclusions.

In JCGK's many years of work, we have always maintained an objective and professional attitude towards all testing work. We believe that only by facing every inspection challenge with an open and aggressive mindset, we can grow to be a trustworthy brand of leak detector in the industry. As Lao Tzu said, "Know its male, keep its female." We would like to continue to play a positive guiding role in the industry and provide customers with the best quality airtightness testing solutions.