This part of ISO 8038 specifies the dimensions of screw thread type RMS as one type of thread for connecting a microscope objective to the nosepiece.
NOTE 1 The values given in this part of ISO 8038 conform, except for the length of the thread lug, to the internationally used screw thread laid down by the Microscopical Society of London in 1858, and published [1] as the Royal Microscopical Society Standard (RMS Standard) in 1936.
The use of this screw thread is recommended for microscopes unless other fittings are required for optical or design reasons.
NOTE 2 A specific combination of eyepiece, objective and tube lens (if provided, e.g. infinity optics) is frequently used to correct aberrations. Therefore the combination of an objective from one manufacturer, although conforming to this part of ISO 8038, and an eyepiece from another manufacturer may cause loss of image quality.
Objectives and eyepieces of one manufacturer can be combined with microscopes of another manufacturer if they conform to this part of ISO 8038 and also to ISO 9345-1 [2].
note:1) The maximum length of the thread lug according to this part of ISO 8038 is 5 mm. The RMS Standard specifies the length of the thread as 3,175 mm and length of the guide cylinder as 2,540 mm, giving a total of 5,715 mm.
BS 7012-4.1:1998 history
2013BS ISO 8038:2013 Microscopes. Screw threads for objectives and related nosepieces
0000 BS ISO 8038:2011
1998BS 7012-4.1:1998 Light microscopes - Specification for microscope objective and nosepiece screw threads - Screw thread type RMS (4/5 in x 1/36 in)