Reference-leak calibration and detection threshold

LEAK TESTING · ENGINEERING CALCULATOR

Convert background-corrected detector signals to helium throughput using a reference leak measured through the working test system.

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Model

Assumptions and use

Reference and test conditions must share the applicable response and measurement path. The pure-helium equivalent divides by tracer concentration; it is not a universal conversion between gases or flow regimes. The threshold uses the entered distinguishable increment and is not a complete uncertainty assessment.

Worked example

With a 1e-8 Pa·m³/s reference, reference net signal 100, test net signal 25 and 20% helium, measured helium throughput is 2.5e-9 Pa·m³/s; the 100% equivalent is 1.25e-8 Pa·m³/s.

Record the units, gas, temperature, background and instrument settings with every result. Confirm the model assumptions before applying a calculated limit to a real test.

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