Roy, UT, Nov. 02, 2026 (GLOBE NEWSWIRE) -- A production line has outgrown pressure decay when the test can’t verify the required leak rate within the available cycle time. Spectro Physics has published a guide to specifying automated helium leak test systems based on the custom equipment it builds for medical device, life-support and automotive manufacturers. The company reports more than 300 systems in operation.
Pressure decay can work when the required leak limit is within its measurement capability, and part volume, temperature and test duration all affect that capability.1 Spectro Physics puts the practical floor for pressure decay at leaks of about 0.001 mbar·L/s and says helium detection reaches leaks about a billion times smaller,1 2 though the achievable limit still has to be demonstrated with the selected detector and test configuration.
Key facts
- Helium mass spectrometry measures escaping tracer gas against an atmospheric helium background of only about 5 parts per million;3 pressure decay estimates leakage from changes in pressure.1
- Temperature changes and parts that flex under pressure can both shift pressure decay readings independently of leakage.1 4
- Under FDA’s Quality Management System Regulation (QMSR), in effect since Feb. 2, 2026, ISO 13485:2016 is incorporated by reference,5 and its clause 7.6 calibration and software validation requirements can apply to a production leak tester that accepts or rejects product.6
- Spectro Physics says an independent study by one large user of its equipment found a 1-in-100-million chance of the system passing a bad part.7
The reject limit is tighter than pressure decay can resolve in the cycle time
When pressure decay can’t verify the specified reject limit within the available cycle time, the manufacturer needs to reassess the test duration, station design or measurement method before accepting the process. Testing for smaller leaks typically requires a longer pressure decay test,1 and settling is often already the largest part of the cycle.4
Where the specified leak rate falls below what pressure decay can demonstrate, helium testing is the stronger candidate because tracer gas methods detect smaller leaks than pressure decay.1 The builder still needs to verify performance on the actual part at the required production rate.
Temperature swings move the readings
Pressure decay readings are highly sensitive to temperature changes, because the pressure inside a part moves with its temperature whether or not it leaks.1 By the ideal gas law, warming a part held at 5 bar absolute by just 0.1 degree Celsius at room temperature raises its pressure by about 1.7 mbar. Even a leak at pressure decay’s practical floor of 0.001 mbar·L/s would take more than two hours to lower a 5-liter part’s pressure by that much. A component tested while still warm from welding or washing can show a pressure change unrelated to leakage, and temperature can stretch the settling time the test needs.4 A helium test reads the tracer gas itself rather than the part’s internal pressure, so a temperature-driven pressure change doesn’t register as a leak. Its accuracy depends instead on controlling background helium in the plant.2
Large or flexible parts give readings the line cannot trust
Flexible parts can be pressure decay tested as long as they withstand the test pressure,1 but flexing and deformation under pressure lengthen settling and can skew the result, which is why some lines restrain the part during the test.4 Larger parts also decay more slowly, which means longer test times.1
Helium testing can speed up testing for large parts.4 A vacuum chamber test shows whether the part leaks, while a sniffer probe can locate the exact source of the leak on a pressurized part.8 Spectro Physics also builds replacement chambers for existing systems when new part geometries need to be accommodated.
Sealed parts with no port can’t be pressurized from the inside
For sealed parts without access ports, helium bombing forces tracer gas into any leak by holding the parts in pressurized helium before the test, and a helium leak detector connected to a vacuum chamber then measures the helium coming back out.9 Spectro Physics’ hybrid systems run both steps for small sealed parts made in volume, bombing up to several hundred at a time and testing them in small batches.
“Our solutions are custom tailored to the particular challenges of the customer,” said Greg Hill, operations manager at Spectro Physics. “From the outside they’re pretty simple-looking machines, but there’s a lot going on in the software and the hardware, and it’s all designed and optimized for the customer’s application.”
The line has to show which parts were tested and how they were dispositioned
Medical device manufacturers need records showing that released product met its acceptance criteria.6 Under the QMSR, applicable ISO 13485:2016 requirements also govern the calibration or verification of measuring equipment and the validation of measurement software.5 6 Clause 7.6 calls for that equipment to be calibrated or verified, where necessary to ensure valid results, at specified intervals or before use against standards traceable to international or national measurement standards, and for software used in monitoring and measurement to be validated before first use and, as appropriate, after changes.6 Whether and how those controls apply to a given leak tester depends on its intended use and the manufacturer’s own quality system.
A helium tester’s specification should name the part identifier, such as a serial number or lot, the test-result fields to record, the system that stores them and the retention period. Spectro Physics says its systems can integrate barcode scanners and RFID antennas to tie each test result to the part it belongs to, and the company’s A2LA-accredited ISO/IEC 17025:2017 laboratory calibrates the helium leak standards a line uses to check its detector.
Frequently asked questions
Question: Is helium leak testing better than pressure decay for medical devices?
Answer: Helium is the better fit when the device’s leak limit falls below what pressure decay can demonstrate within the cycle time, and pressure decay remains the simpler test when it can meet the limit. The manufacturer should verify the chosen method on representative parts at the required cycle time.
Question: Does the QMSR require a specific leak test method for medical devices?
Answer: The QMSR does not mandate helium testing or pressure decay. The manufacturer selects a method appropriate to the device and applies the relevant equipment-control requirements under its quality system. A change in test method should trigger a review of the applicable calibration, verification and software validation controls.
Question: How do manufacturers stop leaking parts from shipping?
Answer: By testing every part against a reject limit set from the part’s requirements, with a method verified to meet that limit at the required production rate. Detector checks and calibration intervals then follow the validated procedure, and tying each result to a serial number or lot means a failed check can be traced to the parts it affects.
Question: How should a manufacturer validate a new automated helium leak test system?
Answer: Define installation, operational and performance qualification (IQ/OQ/PQ) acceptance criteria before the system arrives. Validation should establish that the system rejects reference parts with known leaks at the specified limit under production conditions. Separately, document detector verification against a certified leak standard and validate the test software for its intended use.
Manufacturers can review Spectro Physics’ automated leak detection systems and request a quote on its website.
About Spectro Physics Inc.
Founded in 2003, Spectro Physics Inc. integrates more than two decades of company history with additional decades of engineering experience in leak-detection system design, calibrated leaks, and ISO/IEC 17025:2017-accredited calibration services. Based in Roy, Utah, the company has deployed hundreds of automated leak-test systems across medical device, aerospace, automotive, and industrial manufacturing sectors. Spectro Physics develops custom, operator-friendly solutions built for long-term reliability, traceability, and seamless integration into production workflows. Its calibration laboratory provides precise, NIST-traceable leak standards supported by disciplined quality controls and fast turnaround. Through engineering depth and rigorous calibration practices, Spectro Physics supports manufacturers that require dependable, repeatable leak-detection performance.
Majed Soufi Zen Media PR@zenmedia.com
