Gas concentration (including gas leak detection) detection technology has a wide range of applications, among which vacuum chamber type gas leak detection technology is a common technology, which detects the gas tightness of products through the detection of trace gas concentration.
The vacuum chamber type gas leak detection technology generally uses halogen gas, hydrogen or helium as the tracer gas. The includes the detection chamber, vacuum pumping valve, vacuum pump, gas sensor valve, gas sensor, tracer gas valve and tracer gas source. During detection, first open the vacuum pumping valve, use the vacuum pump to pump the detection chamber to a high vacuum, and then open the tracer gas valve and tracer gas source, Fill the tracer gas into the workpiece to be inspected, finally open the gas sensor valve, and use the gas sensor to detect the concentration of the tracer gas outside the workpiece to be inspected. If the detected tracer gas signal exceeds the set value of the gas sensor, the workpiece to be inspected on the surface has leakage.
The characteristic of vacuum chamber type gas detection technology is that the workpiece is placed in the detection chamber. Before the workpiece is filled with tracer gas for leak detection, the vacuum pumping valve is opened first, and the detection chamber is pumped to a high vacuum with a vacuum pump. The requirements for vacuum degree are very high, otherwise the detection accuracy is easily affected. Because of the high vacuum, the tracer gas diffusion speed is fast, and the gas sensor can quickly detect the concentration of the tracer gas by the diffusion movement of the tracer gas in the vacuum environment without auxiliary inspiration. The vacuum chamber type gas leak detection system has high detection accuracy, fast production rhythm, and can realize full automatic detection without manual intervention. However, the equipment structure is very complex and strict, and the equipment manufacturing cost is high. Because of the need for a high vacuum, the vacuum system design is complex, and the manufacturing cost is also high, the promotion and use of the vacuum chamber type leak detection technology is limited by the high cost of equipment investment. At the same time, this technology cannot locate the leak point of the workpiece to be inspected.
