Optical instruments are affected during their use by a number of different environmental influences which they are required to resist without significant reduction in performance, while still remaining within defined specifications. The type and severity of these parameters depend on the conditions of use. The environmental effects on optical instrument performance in tropical and subtropical climates are totally different from those found when they are used in the arctic regions. Individual parameters cause a variety of different and overlapping effects on instrument performance. The manufacturer attempts to ensure, and the user naturally expects, that instruments will resist the likely rigours of their environment throughout their life. This expectation can be assessed by exposure of the instrument to a range of simulated environmental parameters under controlled laboratory conditions. The standards of the ISO 9022 series contain details of a number of laboratory tests which reliably simulate a variety of different environments and therewith allow assessment and comparison of the response of optical instruments to appropriate environmental conditions. The tests are based largely on IEC standards, modified where necessary to take into account features specific to optical instruments. Part 22 of DIN ISO 9022 specifies methods for the testing of optical instruments as well as instruments with optical components and assemblies from other fields (for example, mechanical, chemical and electronic components) under equivalent conditions, for their ability to resist combined bump or random vibration, in cold, dry heat or temperature change. So far, these methods were contained in Parts 10, 13, 15, 16 and 19 of DIN ISO 9022. Now better streamlining has been carried out with deletion of outdated or no longer required methods; the methods which are still necessary have been compiled in the now available Part 22 of DIN ISO 9022. The committee responsible for this standard is NA 027-01-02 AA "Grundnormen für die Optik" ("Fundamental standards for optics") of the Optics and Precision Mechanics Standards Committee at DIN.