An article to read the many factors affecting the airtightness test, leakage results how to be accurate and reliable?

Nowadays, the manufacturing industry has high requirements for the airtightness performance of products. The airtightness test can detect whether the products will have leakage, air leakage and other quality problems when in use, and ensure the reliability and safety of the products. However, the results of the air tightness test will be affected by many factors, this article will analyze these factors one by one and provide solutions to ensure the accuracy of the test results.

1. Effect of temperature variations on test results

We all know that.Airtightness TesterThe main test medium is gas, the gas is very sensitive to temperature changes, the temperature is high, the gas molecules move more vigorously, the density will fall, the pressure will increase; in turn the temperature is lowered, the density will rise, the pressure will fall.

(indicates contrast)Airtightness Test EquipmentIt has a keen sense of smell for pressure changes and can detect even Pa-level pressure fluctuations. So if the ambient temperature fluctuates during a test, it will have an effect on the pressure input to the test system. For example, if a gust of wind blows over the instrument during the equilibrium and pressure-holding phase of the test, the pressure will be withdrawn; if you accidentally touch the test line or the product under test, the pressure will rise again. SoIt is best to choose a more stable temperature environment for testingThe

2. Impact of the space of the product under test on the test results

Due to the low density, high permeability and mobility of the gas, it will show high volatility inside the internal space of the product under test.The larger the space, the more violent the gas fluctuations will be, the less likely the pressure will stabilize, and the perception of pressure changes will be reduced.

For example, there is 1000ml of space inside the product, and after filling, only 300ml of space is left. Assuming that the product is filled with 20kPa of pressure at the same time, the unfilled product will take significantly longer to inflate and equilibrate, and if the final leakage is determined to be the leakage of a certain volume of air, the change in pressure drop will be more pronounced in the 300ml of space filled with filler blocks, compared to the 1000ml and 300ml of space.

Leakage status of micro, medium and large leaks of the hermetic gauge

3. Impact of test lines on test results

The length, caliber and material of the line from the test port of the instrument to the inflatable end of the product under test will all have an effect on the test results.The longer the line and the smaller the caliber, the greater the resistance to the flow of gas through it and the greater the pressure fluctuations.

Therefore, the pipeline material should be chosen with good smoothness and hardness, so that the gas flows more smoothly and is less prone to diffusion and stagnation. The parameters of the pipeline should be reasonably selected in order to reduce the interference of gas fluctuations on the test.

4. Instrument accuracy and fixture precision

The accuracy of the test instrument itself directly determines the accuracy of the test results. If tiny leaks are to be detected, high precision instruments must be used so that the measurement data is reliable.

In addition, the machining accuracy of the fixture that holds the measured part is also critical.If the accuracy is not sufficient, there will be a gap between the DUT and the test line, which will affect the accuracy of the test.And precision-machined tooling and fixtures ensure the stability and reliability of the testing process.

5. Impact of maintenance on test results

After prolonged use of the instrument, theThe seals may be contaminated and the individual air line fittings may be loose.Once the seal is contaminated, it will directly lead to "false leakage" test results; if the joints are loose or poorly sealed, gas will leak out and interfere with the accuracy of the test. Therefore, regular maintenance of instruments and fixtures is essential.

6. How to ensure the accuracy of leakage results

• Selection of high-precision airtightness testing instruments and regular calibration
• Strictly control the test environment temperature, try to maintain a constant temperature
• Optimize the structural design of the product under test to reduce the internal space and gas fluctuation.
• Optimized test line parameters to reduce gas flow resistance and diffusion
• Regular maintenance of instruments and fixtures to ensure good sealing performance
• Strict requirements on the machining accuracy of the jigs and fixtures to avoid the existence of gaps

Summarize

There are many factors affecting the accuracy of the air tightness test, including temperature changes, the size of the measured object space, piping parameters, instrument precision, maintenance, etc. Manufacturing companies should take comprehensive measures from the test environment, product design, test equipment, instrument selection and maintenance, etc., to ensure that the air tightness test data is accurate and reliable, to protect the product quality.

with regards toAirtightness Test EquipmentJCGK, a national brand of JCGK, is worth mentioning. JCGK's products are highly accurate, stable and provide one-stop airtightness testing solutions, which are highly praised by domestic and foreign customers.