Helium leak detection technology is a highly sensitive method used for detecting leaks in an enclosed system. Helium is used as a tracer gas as it is inert, non-condensable, non-flammable, and harmless. Because of its small atomic size, helium passes easily through the leaks. Thus, the change in its concentration is measured and indicated as a leakage rate. Helium is lighter than the next inert gas neon. It is also very cost-effective and can be easily delivered in various cylinders and in pure form. Hydrogen that is not inert is the only molecule smaller than helium.
Helium leak detector works on the principle of field mass spectrometer. The electric beam in the filament of the analysis tube ionizes the leaking helium gas. The ions are accelerated by increased voltage, escape through the split and later pass through the analyzer's magnetic field. The collector can only catch the helium ions and detect helium, as the circular paths of the ions rely on their mass. The ion current is transformed into an electric current using a specific detector. The current is accelerated by utilizing leak detector devices and displayed on the screen. The measured current is equivalent to the concentration of helium and hence equal to the leak.
What makes helium gas ideal for package leak testing?
- Non-toxic, inert, non-condensable, present in the atmosphere in trace amounts
- Helium gas is one of the smallest molecules to consistently and rapidly break the pathway
- Helium is non-flammable, widely available, and inexpensive
- Since it is an inert gas and does not interact with the testing component, it is, therefore, safe to use
- The noise of the instruments caused by the environmental helium is naturally minimal due to its low atmospheric level of less than 5 ppm and thus gives accurate reports
Key benefits of helium-based testing
- Helium leak detection is a highly sensitive detection technique, particularly developed to identify extremely small leaks which cannot be detected with standard leak test methods
- The leak test limit may be set at a level of 1 x 10-10 mbar L/sec, which enables unique comparisons across components, materials, formats, and manufacturing characteristics using a high-speed vacuum approach
Applications of Helium leak detection
Following are some of the common applications of helium leak detection technology:
- Glass Vials
One of the most common package systems for biotechnological and pharmaceutical products. Helium is the most appropriate and sensitive way for qualifying components for empty components and for product-filled vials.
- Pre-filled Syringes
Pre-filled syringes represent the biggest growth area of parenteral packages with the development of more sophisticated drugs for a wide range of injectable substances and increased demand for self-administration. Helium testing techniques can be developed such that these unique package systems have extremely effective test programs.
Bottles are one of the most used packaging methods and helium still remains the standard for quality testing purposes.
- Blister Packs
Helium is still the optimum test technique for qualifying the CFF blister cards' material components. The test procedure is based upon the detection of helium encapsulated in the packaging system as it escapes from the package via micro-channels.
- Foil Pouches
The sensitivity of the helium leak testing method provides an excellent platform to test quality control systems based on foil. This technique normalizes the helium leak rate to 100% so that all test specimens throughout the manufacturing line setup may be directly compared.
- Combination Products
Multi-chamber systems with specific needs for tests are perfectly suited for using helium leak test to guarantee that all components satisfy the rigorous leakage standards.
helium leak detection, helium leak test, helium detector, helium sniffer, package leak testing