Negative Leak Rate in Leak Testing
Before delving into the causes of negative leak rate, we should first explain what negative leak rate is and how it is calculated. Negative leak rate occurs when the pressure drop of the part being tested is less than that of the leak-free reference part. Negative flow occurs when the pressure of the test part increases or when it has smaller leaks than the reference, and this is called negative leak rate.
There are four factors that need to be considered in the situations that arise:
Control of Part Temperature and Leak Rate
The main cause of problems that lead to negative leak rate in production areas is the change in part temperature. As we have mentioned in our other writings, temperature is one of the important factors that affect the test. The temperature of parts from different production methods such as welding, washing, etc. can cause negative leak rate. When this result is obtained, it can be suggested to bring the part temperature to the same temperature as the reference or to change the test parameters as a solution. Adlema has methods and algorithms for leakage tests that are independent of your production processes. Contact our support team now for optimization of your leakage tests.
Effect of Environmental Conditions on Negative Leak Rate
Controlling environmental conditions in production areas is quite difficult. Sun and temperature have varying effects throughout the day and seasons. The temperature of the area where the products are stored can be well above average in the summer months and well below in the winter months. Product temperatures can drop overnight and cause different test results throughout the day.
Due to the volume, size, and material of the product, this effect on the products can be quite variable. Contact us immediately for pre-launch use of our world-leading system developed for irregular environmental conditions throughout the day and year.
Evaluate Your Parts
Evaluate Your Parts: Changes may have occurred in your production processes since you installed your leak test system. Perhaps your parts are now much more leak-tight than they were on the first day. This is great news, but it also means that your parameters need to be reassessed. Contact our support team now to have your parts evaluated and to learn about the results.
Re-evaluate your Leakage Testing system
What is your leak rate ? Have you changed your test line? Have there been any changes to O-rings or gaskets? Has your connectors system changed? Has the behavior of the part’s volume or test time changed? If your answer is yes, the system may need to be recalibrated. Parameters can change to separate faulty parts from approved ones.
If negative leak rates occurs in test results, Adlema team is always here to assist you. Contact us immediately.
