Can an ordinary air-filled blister be tested for helium?
A helium measurement needs tracer gas to be available at the relevant side of the package boundary. In a prepared blister tested under external vacuum, escaping tracer reaches an analyser. An ordinary air-filled production blister is not the same test object merely because it fits the chamber.
Identify tracer introduction, concentration, specimen boundary and any preparation that changes the sample. Mass-spectrometric helium measurement and visible dye entry observe different events. Compare the actual preparation and conditions, not just the test names.
No. An accumulation arrangement can introduce tracer through a test connection and measure its build-up in an external chamber at normal pressure. A vacuum-mode blister test uses an evacuated chamber and analyser. They share a tracer concept but differ in preparation, driving conditions and sensing.
Interpret the leak rate with its units, tracer conditions, demonstrated defects and specimen preparation. An acceptable limit needs a package-specific basis; helium leakage is not directly convertible to WVTR or shelf life.