Helium leak testing is a critical process in various industries to ensure the integrity of sealed components. But do you know what happens when background helium levels interfere with accurate leak detection? How can you distinguish between actual leaks and background noise?
Background noise refers to the presence of helium in the system and leak detector. It may hinder the identification of real leaks. You would need to reduce the effect of background noise to get reliable and accurate results.
Let’s explore these challenges and their solutions through a case study.
Case Study: How a Manufacturer Struggled with False Leak Indications
An engineering company that specializes in vacuum-sealed components faced recurring issues of false positives in their helium leak testing process despite using high-quality detectors.
The company sought expert advice from Tekman India to enhance its testing accuracy. The Tekman team listed out the key challenges as below:
Key Challenges:
- The inconsistent results were due to Helium background levels that kept fluctuating.
- The facility had poor environmental control, and this led to variations in pressure and temperature.
- The company’s testing team lacked approaches to differentiate real leaks from false signals.
The pumping speed means how quickly a pump can evacuate volume and maintain pressure. So, a high pumping speed means the evacuation will be fast which lowers the cycle times. Thus, it helps to reduce production costs.
Solutions provided:
1. Utilize High-Quality Helium Leak Detectors
Usage of modern helium leak detectors that are equipped with advanced filtering and signal processing features. It helps to distinguish helium leak signals from background interference. Noise filtering algorithms and signal averaging techniques enhance accuracy by smoothing transient noise and focusing on specific helium signatures in real time.
2. Control Environmental Factors
Temperature and pressure fluctuations impact helium leak detection. Leak tests need to be done in controlled environments where humidity is low and airflow is minimal. This will ensure consistent results. For highly sensitive applications, they were advised to use cleanrooms. All these will minimize variations in background noise.
3. Monitor Helium Background Levels
External factors cause a rise in background helium and complicate leak detection. Consistent tracking of these levels will allow for adjustments in test parameters and give accurate detection results. Regular monitoring of background helium levels is crucial.
4. Implement Appropriate Test Methods with Nitrogen:
- For significantly lower background levels, switch to the hard vacuum method and flush the nitrogen (N2) before conducting the leak test. Additionally, using an extra turbo molecular pump can help achieve a deeper vacuum and remove helium from the test environment.
- In sniffing applications, helium contamination in the sniffing line from previous tests can be removed by exposing the sniffer probe to nitrogen (N2).
5. Prevent Helium Contamination
The presence of uncontrolled helium distorts test results. Hence, the following measures were advised:
- Avoidance of helium leaks from supply lines.
- Ensure helium is vented outside the work area or recovered and not simply released within the testing environment.
- Maintain high-quality joints in the system to prevent unnecessary leaks during hard vacuum tests.
- Eliminate residual liquids like water as they tend to evaporate under vacuum and generate false signals.
Outcome: A Significant Reduction in False Positives
By addressing the above critical areas, the company saw a dramatic improvement in its leak detection process. They could minimize false positives and identify real leaks with higher precision. The controlled testing environment, combined with upgraded detection techniques, ensured more reliable results.
At Tekman India, we help businesses optimize their helium leak testing using these strategies. Are you struggling with background helium noise, connect with us and enhance your testing accuracy today!
