This standard specifies the thread size of the C-type interface connected to the microscope imaging outlet (except for monocular or binocular tubes) and the position of the initial image plane.
GB/T 22063-2008 history
2018GB/T 22063-2018 Microscopes—Interfacing connection type C
2008GB/T 22063-2008 Microscopes-Interfacing connection type C