Leak-test metrology: ISO 20486 and ISO 3530

LEAKLAB · TESTING AND ENGINEERING

Reference-leak calibration, instrument verification and a working sensitivity check are distinct tasks.

Reference response in the complete system

The source portfolio identifies ISO 20486:2017 for gas reference-leak calibration and ISO 3530:1979 for mass-spectrometer leak-detector calibration. Their applicability and document status are reviewed for the particular metrological task.

Select a reference leak with known throughput and stated conditions. Review range, gas, temperature dependence, stability and traceability. Connect the reference so that the check characterises the complete arrangement, including the object connection, lines, pumping and fixtures.

What a response check does not imply

Checking system sensitivity, calibrating a reference leak and performing national legal-metrology verification are different procedures. Product testing does not automatically include instrument verification or an accredited calibration certificate. The required metrological service, provider and resulting document are agreed separately.

Preparing and verifying the test

1. Review the drawing, materials, internal volumes, test boundary and required result.
2. Agree the document edition, allowable pressure difference, vacuum and temperature, acceptance criterion and required system sensitivity.
3. Clean and dry the object, prepare fixtures and exclude leakage from the test connections.
4. Check instrument metrological status and the working characteristics of the complete arrangement; use an appropriate reference response for the selected method.
5. Perform the agreed scan or measurement cycle and record the actual conditions. Confirm suspected leaks by repeat tracer-gas exposure where applicable.
6. Check system stability after the test and report the result against the agreed criterion.

What the customer receives

The agreed scope can include a test programme, operating or inspection instructions, measured results, a map of located leaks and a technical conclusion. The report identifies the object and tested regions, applicable programme, instruments and metrological status, pressure and temperature, response checks, observations and limitations.

Define your task

Send a drawing or sketch, material, dimensions and volume, working pressure, allowable vacuum and temperature, leak-tightness requirement, number of items, site and schedule. These inputs determine the method, fixture, equipment and reporting scope.