This part of ISO 10109 specifies requirements to be met with regard to resistance of the optical, mechanical, chemical and electrical properties or performance data of instruments to environmental influences and hence determines geographical and technical areas of application. It applies to optical instruments and instruments with optical components including accessories in the field of optical metrology for laboratories, production plants and testing. Environmental test methods as specified in ISO 9022 are assigned to the various areas of application for the purpose of ascertaining the suitability of the instruments in their respective area of application. This part of ISO 10109 does not apply to instruments which are covered by other parts of ISO 10109. This part of ISO 10109 does not deal with the requirements to be met by the packaging of the instrument during transport from the manufacturer to the user.