For a majority of films (including laminated films), pressure difference does not affect barrier property of materials. As to some coated materials (such as aluminum coated film), its barrier property will change obviously only when a very big pressure (400MPa) is imposed. But within the pressure range of differential-pressure method, there will be no influence. To obtain more scientific and comprehensive conclusion, Labthink Lab is carrying out verification test in a boarder range.

Data stability closely related with precision, repeatability, reliability, test condition, specimen condition and test operation of instrument. No conclusion can be made without objective, scientific and comprehensive test. It is very ridiculous for somebody to believe that there is no differential pressure existing in equal-pressure method and thus test data are not affected while the pressure difference in differential-pressure method has an effect on test data.