Which of the following is not a limitation of non volumetric testing?

• A. Usually cannot measure a leak rate accurately or at all
• B. Adversely affect product quality if the test gas is not inert
• C. Cause or enhance a leak during testing by exerting pressure higher than normal
• D. Product evaporation

Answer: (D)

Non-volumetric testing checks tank tightness by monitoring how the pressure in the system changes, not by measuring how much product mass or volume is lost. Because of that, you can’t get an exact leak rate from this method, which is a limitation. If the test gas isn’t inert, it can contaminate or react with the product, affecting quality. Pressurizing the system above normal levels can also stress seals and create or enlarge leaks, another limitation of this approach. Product evaporation, however, isn’t a direct constraint of non-volumetric testing because the method does not rely on tracking changes in the product’s amount or phase; the evaluation is based on pressure behavior, not on evaporation dynamics, so evaporation isn’t an inherent limitation of this testing method.