Key Factors That Affect The Choice of Leak Test Methods.

A wide range of key factors affect the choice of leak test methods, and reputable manufacturers that offer the full gamut of test techniques will not try to steer you one way or another. The laws of physics and the nuances of each type of leak testing method are the things that identify the best leak test method for any given application, if you have a truly unbiased and knowledgeable leak testing expert as your guide.

Using 100+ Years of Leak Testing Experience to Solve Application Challenges

I’ve been at Uson for more years than I care to remember, and so have many of my colleagues. It’s not that we got stuck in a rut, it’s more like we got hooked on helping people figure out to solve some very thorny problems. Almost every day, something new comes through our doors and, I have to say it keeps life interesting. Even if an application is something we have never tackled before, we are able to draw upon a collective experience of well over 100 years.

Misinformation About Leak Testing In the Medical Device Industry – Just Because It’s Always Been Done That Way, Doesn’t Mean It’s The Only Way, or The Best Way.

Here’s an example. Recently we received a call from a process engineer from a medical device manufacturer, seeking a leak tester using a certain type of sensor. He was certain that was the way for him to go because that was the type of leak test they had done for the previous six years. It’s possible that the hurdle of validation may have also played a part. Seeing that he was at the absolute lower limit of where a mass flow leak test could be performed at the gage R&R repeatability and reproducibility he needed, we were able to demonstrate an alternate pressure decay tester producing the same gage R&R, but with a 12-fold decrease in test cycle time. Furthermore, he got a leak test instrument that can accommodate a design change and a wider range of test pressures. Another company may have gone along with his request and hoped for the best. After all, he would have received what he asked for.

This type of call doesn’t happen every day, but it happens often enough to keep us alert to the problems of misinformation being circulated in the medical device industry. Specifically, the misinformation that one type of leak test method is inherently better for nearly all applications. This is simply not true. There is so much misinformation along these lines that it has prompted USON to introduce a no-cost quick turnaround service to select and spec a leak testing model within 48 hours, and if requested, a complete spec of leak tester configurations as well.

Dry Air Leak Test Methods

There are many dry air leak testing methods that can be used on a wide range of medical devices at some point in their lifecycle including:

• pressure decay
• vacuum decay
• differential pressure decay
• mass flow (including back pressure and differential)
• upstream and downstream cracking pressure
• pressure rise
• burst
• laminar flow
• force decay
• occlusion

For some applications with extremely stringent leak rate standards, tracer gas testers are added options, though this is not common in the medical device industry. Why would anyone expect a staff manager to be familiar with every air leak test method in sufficient detail to make the best decision for a new product design?

Uson’s Experts Can Guide You Through The Most Challenging Medical Device Applications.

Although your team may include NDT experts, my experience tells me anyone can benefit from an experienced guide who thinks about leak testing at least 40-60 hours a week. Better yet, you need a team of such leak testing-obsessed experts who have “been there and done that” when it comes to all the medical devices being used today.

Rapid innovation in the medical device industry is not new. If there is one constant that we see in this industry, compared to others we have served for half a century, it is just that. Many entirely new devices are born each year and generations of devices developed decades ago continue to be tweaked as newer electronics, materials, software etc. continue to drive product improvements.

When your designs change it is highly likely that you will need to test your devices or their components at different test pressures or with subassemblies attached in different ways, or with altered internal volumes, or any number of other modifications that may make a leak test method used today a poor match tomorrow.

Leak testers such as Optima vT and Vector have been designed on a kind of modular basis – they can easily be reconfigured with different sensors, additional test modules, and modified pneumatic circuits to facilitate your product changes.

Let’s Talk About Your Next Project!

The team at Uson has dedicated countless years to developing and expanding our Leak testing knowledge. We thrive on hearing from potential and existing customers about your most challenging applications. It is what fuels our passion and motivates us to continue. Contact us today and let's talk about your next project.