This International Standard specifies recommended diameters to allow the interchangeability of spectral filters used in microscopes, as well as permissible filter material defects and processing faults.
This International Standard differentiates between two forms of spectral filters:
Form A: Filters to be used both in the observation light path and in the illumination light path;
Form B: Filters to be used solely in the illumination light path.
BS 7012-6:1998 history
1998BS 7012-6:1998 Light microscopes. Specification for spectral filters