LEAK TESTING · ENGINEERING CALCULATOR
A steady-state gas balance relates chamber pressure to the total gas load. Allocate only the selected fraction to real leaks; the rest must cover outgassing, permeation and process gas.
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Model
Calculate
Assumptions and use
Use effective pumping speed at the chamber for the selected gas and operating pressure. The allocation is a design input, not a universal acceptance limit. If the background already exceeds the target pressure, eliminating leaks alone will not achieve the target.
Worked example
At 1e-7 Pa, 300 L/s and 10% allocation, the allowable total leak throughput is 3e-9 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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