Standard for determining good and bad products of airtightness testing equipment

An airtightness tester is an instrument used to test the airtightness of a product. It determines whether the product is qualified by measuring the leakage amount/rate of the product under certain pressure conditions.

A video understanding of the judgment criteria for qualified product airtightness

What is good airtightness? This is a question that we often think about in our daily airtightness testing work. The airtightness performance reflects whether there will be gas leakage during the use of the product.

In the past few years, we have been engaged in the research and development of airtightness detectors. Through these years of work experience, Demerton deeply understands the importance of judging whether a product has good airtightness. I would like to share with you some of the experiences and insights I have accumulated during this process through this article.

What is leakage rate and leakage volume?

The leakage amount (Па) and leakage rate (мл/мин) are essentially a concept, and this leakage value is equivalent to defining a critical value for airtightness qualification (OK) and poor airtightness (NG) for the product. They are important indicators that reflect the sealing performance of a product under certain pressure conditions, and are the main benchmark and basis for determining whether the airtightness of the product is qualified or not in our process production, It is also the basis for the instrument to determine whether the airtightness of the product is qualified, whether the airtightness test is OK or NG.

Leakage refers to the volume of gas leaked through the product per unit time, measured in Pascal (Па);

Leakage rate refers to the ratio of the volume of gas leaked through a product to the volume of the product per unit time, measured in milliliters per minute (мл/мин).

How to determine whether the airtightness of the product meets the process requirements?

As mentioned earlier, whether the airtightness of the product is qualified is determined based on the value of the leakage amount. This leakage indicator is not built-in to the instrument, but set by technical personnel. The instrument will use this value as the standard to determine whether the product is qualified or unqualified, that is, during the testing process:

If the leakage value reaches or exceeds the preset leakage value, the instrument will consider the product unqualified and display a red NG prompt on the interface; If the value remains within this set range, the instrument will consider the product to have passed and display a green PASS prompt.

For example, if we set the leakage rate to 30Pa, products with a leakage rate of 30Pa or more will be judged as NG, while products with a leakage rate less than 30Pa will be judged as passed.

Setting of leakage volume and leakage rate values

The criteria for determining whether a product is leaking should come from the reference leakage amount provided by the customer. If the customer does not provide data, we need to test and obtain the data ourselves.

Method for determining leakage amount:Standard for airtightness testers

First, test a set of products (such as 10) that we ensure are airtight and record the leakage value.

Take another set of defective products with leaks (such as 10) for testing and record the leakage values.

We obtained two sets of leakage values from the above tests, and we analyzed these two sets of values:

First, let’s look at the qualified products. Assuming that the leakage values of the qualified products are all 10, 8, 12, 15Pa And the maximum value will not exceed 20Pa.

Let’s look at the data of defective products again, assuming that the data of defective products may be 50, 100, 300Pa The data far exceeds that of qualified products.

Then we can set a value of 20-25Pa as the leakage judgment standard depending on the situation. Through the above experiments, we also have a basic understanding of the data of qualified and unqualified products.

Product airtightness qualification judgment

For products with leakage values much higher than the specified threshold during detection, they can basically be determined as leaking products. However, for some products with leakage values very close to the threshold, can we determine if they are leaking if the leakage reference is defined as 20Pa and the test value shows 21Pa or 25Pa?

Not necessarily, it may also be caused by factors such as temperature changes, product characteristics, etc. For safety reasons, it is recommended to take out such products first and then make a judgment later. If subsequent testing finds that these products are all qualified and in large quantities, it is possible that the sample size of the leakage determination standard test is not large enough, resulting in a slight deviation in the data. We can modify the leakage volume or leakage rate standards appropriately.

summary

Through years of exploration and summary, I hope to provide some reference for everyone to judge and control the airtightness performance of products. Of course, this is a very complex topic, and the judgment criteria also need to be set in conjunction with specific products and usage environments. If you encounter any problems during airtightness testing, please consult the manufacturer or professional of the airtightness tester.

Demerton is already in a leading position in airtightness testing technology and solutions in the industry. We not only provide precise and reliable testing instruments, but also accumulate valuable experience in judging standards, quality control, and other aspects. These achievements have effectively improved the product performance and reputation of customers. Looking ahead to the future, Demerton will continue to innovate, work with more customers and partners, promote industry technological innovation, and create greater value!