Common vacuum leak detection methods

Helium Mass Spectrometer Leak Detection:
This technology is an indispensable technology in the field of vacuum leak detection. Due to the high efficiency of leak detection, simple and easy operation, sensitive instrument response, high accuracy, and resistance to interference from other gases, it has been widely used in leak detection. The helium mass spectrometer is an air tightness testing instrument made of helium gas as a leak gas according to the principle of mass spectrometry. It consists of an ion source, an analyzer, a collector, a cold cathode ionization gauge, a mass spectrometer chamber, an extraction system, and electrical components. The electrons emitted by the filament in the mass spectrometer room oscillate back and forth in the room, collide with the indoor gas and the helium gas that has entered the room through the leak to ionize them into positive ions. These helium ions enter the magnetic field under the action of an accelerated electric field. Due to the Lorentz force, a deflection occurs and an arc-shaped orbit is formed. Changing the acceleration voltage allows ions of different masses to reach the receiving pole through the magnetic field and the receiving slit to be detected. The helium injection method and the helium absorption method are two commonly used methods in helium mass spectrometer leak detection.

Vacuum sealing mud detection method:
Seal the suspected leaking points one by one with vacuum clay, and pay attention to the change of vacuum degree. If the vacuum degree of vacuum sealing clay is increased quickly, it will drop significantly when removed, indicating that this is a leaky point. This method is rarely used in practical applications.

Vacuum gauge leak detection method:
Some vacuum gauge readings are related to the type of gas, such as thermocouple gauge, ionization vacuum gauge. These vacuum gauges become detectors by using appropriate gas or liquid as the leaking substance. Generally, there are vacuum gauges on the coating machine, which is very convenient to use and is a commonly used leak detection method. Leakage materials used in thermocouple gauges include carbon dioxide, butane, and alcohol. Thermocouple gauges react slowly and should be observed carefully. Leak materials used in ionization meters include helium, argon, and alcohol.

High frequency spark leak detection:
This method is only suitable for glass vacuum systems. Vacuum the system first, the spark end of the high-frequency spark leak detector moves along the glass surface, and the spot where the sparks are concentrated into a beam is the location of the leak.