The helium mass spectrometer leak detector is based on mass spectrometry technology and employs the helium tracer method for leak detection. Due to its high precision and reliability, it has become a widely used inspection tool in the field of sealing.
1. Working Principle
Helium is used as the tracer gas because its small molecular size allows it to easily pass through tiny leaks and enter the mass spectrometer chamber. The gas inside the chamber is ionized, forming an ion current. Under the influence of specific electric and magnetic fields, only helium ions are detected. The size of the helium ion current determines the leak rate. Due to helium’s low background concentration (only 5 ppm in air), a high signal-to-noise ratio is ensured, enabling the detection of extremely low leak rates (down to 10⁻¹³ Pa·m³/s).
2. Key Features
① High-Sensitivity Detection:
Capable of locating minute leaks with precision far exceeding traditional methods such as bubble testing or pressure decay.
② Quantitative Analysis:
Accurately measures leak rates to meet industrial standards (e.g., stringent requirements in aerospace and semiconductor industries).
③ Non-Destructive Testing:
Non-invasive method suitable for precision equipment or products with sealing requirements.
Leak Detection Methods
Depending on the test conditions, the object under inspection is either evacuated or pressurized with helium. Two primary methods are used:
Sniffer Probe (Spray Method): Helium is sprayed on suspected leaks, and any ingress is detected by the spectrometer.
Vacuum Hood (Suction Method): The detector draws in helium escaping through leaks, measuring the leak rate in real time.
Advantages
✔ High sensitivity and rapid response, suitable for both positive-pressure and vacuum leak testing.
✔ Helium is safe, inert, and environmentally friendly, posing no harm to operators or equipment.
Limitations
✖ Higher cost, and large containers may require additional vacuum systems for testing.
✖ Test objects must be clean to avoid contamination (e.g., oil vapors) that could affect the spectrometer.
Post time: May-26-2025