The micrometer or reticle is a round piece of glass that fits inside an eyepiece. Embossed or imprinted in the glass is a linear scale, crosshair, counting motif, etc. All of which are used for measuring and or counting purposes.
Sizes of the micrometer or reticle vary according to the type of eyepiece. For instance, an older hygenian eyepiece will house a smaller micrometer 17mm or 18mm in diameter whereas a 10x widefield eyepiece will house a 19mm - 21mm reticle. The newest eyepieces in clinical type microscopes will house reticles upwards of 26mm and stereo microscope eyepieces will house large sizes of approximately 24mm - 28mm reticle.
The micrometer or reticle is installed into only one eyepiece and does not matter which one.
The micrometer or reticle is inserted in the lower portion of the eyepiece. Unscrew the lower housing and then insert the reticle with the scale facing upwards and make sure it is sitting properly in the lip or shelf. This ensures the correct focal length thus yielding a sharp/crisp image of the micrometer when viewing through the eyepiece (once inserted back into the eyepiece tube). If not the image will appear out of focus. Again, make sure the micrometer is facing upwards and that the correct numerical order (0, 1, 2, 3, 4, etc.) is from left to right. Otherwise, the numbers will appear backward and you will have to start over. Be careful, as dust and debris are attracted to the glass. The use of a compressed air duster/blower is recommended for removal of dust and debris. Once inserted properly into the lip/shelf, reassemble the eyepiece.
There are unusual situations with older eyepieces where the eyepiece must be unscrewed from the middle, the same installation procedure applies as above.
There are instances that the eyepiece cannot be taken apart and therefore cannot house a micrometer. You may want to consider replacement eyepieces.
Please contact New York Microscope Company toll-free at 877-877-7274 or info@nyscopes.com if additional assistance is required.