Microscope micrometers are commonly used for measuring or counting specimens. Eyepiece micrometers (also referred to as "reticles") are small glass discs with markings on them. The micrometer is mounted in one of the two eyepieces and superimposes an image of the markings over the image of the specimen. Stage micrometers are slides with markings of a known dimension that, when viewed under the microscope, can be used to calibrate eyepiece micrometers. 
Calibration Since the size of the eyepiece micrometer image (e.g. a linear scale) appears the same even though the specimen can be magnified to a greater or lesser degree, the markings on the micrometer do not by themselves indicate any particular measurement. When a stage micrometer with known dimensions is viewed through an eyepiece micrometer, however, the measurement indicated by the eyepiece micrometer at that magnification can be noted and later used to make accurate measurements.
Eyepiece Micrometers Dimensions given are the actual size of the markings on the micrometer disc. Eyepieces for our various models require micrometers of different diameter. The model numbers listed below refer to microscopes with standard 10x eyepieces. If you are using optional eyepieces of a different magnification and do not see them listed, contact us to find out the correct size. 
25mm Diameter Micrometers for RZ Series 10x eyepieces


21mm Diameter Micrometers for ML2000, ML5000, ML7000, ML7500, ML8000, ML8500, MT4000 and MT9000 Series 10x eyepieces 



19mm Diameter Micrometers for RZ Series 15x and 20x eyepieces, and all TM200 and TM400 Series eyepieces
STAGE MICROMETERS

