This part of ISO 9022 specifies methods for the test-ing of optical instruments and instruments containing optical components, under equivalent conditions, for their ability to resist contamination, i.e. contact with corrosive chemical substances (hereafter called test agents).
However, complete instruments or assemblies are only tested as specified in this part of ISO 9022 in exceptional cases (see 5.3). Normally, representative samples such as material items or surface coatings on representative substrates are used for testing.
The tests described are designed for the selection of materials and components for instruments likely to suffer contamination during service life, rather than for regular production control.
The purpose of testing is to investigate the resistance of an instrument and, in particular, of instrument sur-faces, coatings or synthetic materials, to a short ex-posure to the test agents.
note:1) Another possible source of service contamination to which optical instruments may be exposed is radioactive elements and isotopes, and hazardous chemical substances (e.g. 2:2-dichlorodiethylsulfide). However, as these materials may only be hand-led, used for testing, and stored by special, officially approved laboratories, they were not used as test reagents.