To aid in testing, Test Pressure and Hold Period can be combined into a rate of change (ROC). For example, where the Hold Period = 10min and the Allowable Pressure Loss = 30psi, the Average Allowable ROC = 3psi/min. That is, if the average rate of Pressure Calculator change during the 10min Hold Period =< 3psi/min, then the hold and allowable loss component of the test specification will have been achieved.
Please read the originial post here: https://www.scriptjunkyard.com/leak-testing-pressure-testing-basic-principles-of-leak-testing/