Leak testing can be a great investment, especially for companies making healthcare devices. They know that a single component failure can come back to haunt them in the form of expensive liability claims. Because there is a wide variety of testers available, these few tips will help find the right one. That means test engineers increase the odds that leak testing will catch defects and that testing won't become a production bottleneck.

Insist on application-specific equipment

Even small leaks can mean the difference between success or failure in medical applications. So test equipment must accurately meet the needs of the quality check at hand. And one size does not fit all needs. So look for a test-equipment vendor with experience in your industry. The vendor should be able to redesign or reconfigure a tester to work with your equipment and products.

Look for equipment that automates testing

Ideally, test equipment should be semi or fully automated to streamline product delivery, sealing, clamping, testing, and marking. It should have time-saving features such as “infills,” which reduce volumes and test different sized containers in the same chamber with minimum changeover time and expense. The equipment should also connect to PLCs and PCs and have a remote start, two features that speed testing. Another way to accelerate testing is to use multi-channel equipment, some of which can run up to 10 channels and cycle through all the tests at the push of a button.

Ease of operation

A leak tester, no matter how capable, is almost worthless if technicians can't figure out how to use it. Programming should be simplified by software with preformatted and easily modified test configurations. Testers that work within Microsoft's Windows, for example are usually intuitive to operate. Other features to look for include touch screens, large displays, selectable engineering units, built-in diagnostics, and remote troubleshooting.

Fixtures must fit

Attaching your product to the tester is critical, and failures at this stage can undo all other attempts at accuracy and expediency.

At a minimum, testers should have automatic clamping, sealing, and interlocking guards that perfectly match orifices on parts being tested. If speed counts, use quick-connect or auto-coupling, self-sealing pneumatic devices. And if the product being tested has an unusual shape or several orifices, you will probably need custom fixtures. A good vendor should be able to help you locate a shop that can provide them.

Keep output options open

A complete leak detector includes options for documenting your testing process. So at a minimum, the tester should be able to archive leak rates and other results into databases such as Access or spreadsheets such as Excel. This cuts documentation time by 50%, compared to manually entering such data. It also eliminates transcription errors. Other options for downloading data include RJ-45 Ethernet connectors, RS-232 serial ports, PCMCIA card slots, and USB ports. Also helpful are screens that show results at the control unit. Marking, whether by ink, percussion, or laser, also speeds documentation.

Consider repeatability

As any QA person will tell you, a test has no meaning unless it can be repeated with the same results. Automated leak-detection improves repeatability by taking the operator or technician out of the equation. And some testers compensate for temperature and humidity, which also helps assure consistent quality.

Demand good support

Like most sophisticated pieces of equipment, a leak tester is only as good as the support it gets after it leaves the factory. Here supplier experience makes a big difference.

Look for a supplier that offers custom system design, installation, and commissioning. Some suppliers provide online tools to help engineers dial in testing parameters.

Get a tester that can be upgraded

Product variations, specification changes, and the introduction of new components all mandate changes in testing parameters. Make sure your test equipment can handle such changes. Otherwise, you must buy new equipment to take advantage of advances in technology. Modular designs are extremely flexible, letting users choose only features they need for initial requirements, but easily add capabilities later.

Following these tips at our company let us transform a 4.5-minute test cycle into a 1.5-minute event, thus improving throughput by 200%.