For calculating the leak rate of an isolator, pressure decay method is used.
I do not know well but in the calculation below (based on pressure decay) i do not find any information back regarding stabilization of the pressure inside isolator before leak test start.
I would like to know if someone has some more experience or explain me more how to create a tight leak test.
Example 1
Required Leak rate is Y% / h
+100Pa (Starting pressure)
Calculation of allowable leak rate value X%/h when starting from 100 Pa
Starting Pressure 101.325 × 103 Pa + 100 Pa
Final Pressure 101.325 × 10(3) Pa + X Pa
{(101.325 × 103 Pa + 100 Pa) - (101.325 × 103 Pa + X Pa)} / (101.325 × 103 Pa + 100 Pa) = (Y / 100) × (60/3600)
× = 15.5 Pa allowable value
Descending pressure = 84.5 Pa