IEC 60749-7:2011 specifies the testing and measurement of water vapour and other gas content of the atmosphere inside a metal or ceramic hermetically sealed device. The test is used as a measure of the quality of the sealing process and to provide information about the long-term chemical stability of the atmosphere inside the package. It is applicable to semiconductor devices sealed in such a manner but generally only used for high reliability applications such as military or aerospace. This test is destructive. This second edition cancels and replaces the first edition published in 2002 and constitutes a technical revision. This second edition has been completely re-written so as to align it with the text of the latest versions of MIL-STD-750, method 1018 and MIL-STD-883, method 1018. The main change is the removal of the two alternative methods formerly designated method 2 and method 3.