Biological Microscope Eyepiece Microscope Micrometer Formula
When using a biological microscope, it is sometimes necessary to measure the length of the observed object. Since the object under observation is very small, it is not possible to measure it directly with conventional measuring tools, this is where we need to use a microscope-specific micrometer. To measure the length of the object to be examined, you need to use two tools, one of which is mounted in the eyepiece, known as the eyepiece micrometer; a piece of the carrier stage, is a special coverslip, you can see in the middle of it has a small circular area, which is engraved with a very small scale, the general total length of 1mm, a total of 100 cells, that is, the distance between each cell is 10um, it is the role of determining the length of the object. It is used to determine the length of the eyepiece micrometer under the biomicroscope.
In use, we need to first eyepiece micrometer into the eyepiece tube, the specific operation is: first pull down the eyepiece from the microscope, away from the lens (that is, we usually look at the place of observation) at the end of a gear-shaped circular structure, unscrew it, and then the eyepiece micrometer into which, pay attention to the front side of the field of view should be put on the diaphragm, and then screwed back to the eyepiece will be put back. Some microscopes are not allowed to be disassembled due to their precise structure, and need to be specially equipped with micrometer eyepieces. Then put the micrometer ruler on the carrier stage, adjust the focus of the microscope to know that you can see the clear scale of the ruler. At this point, adjust the two ruler's end in the whole scale overlap, and then look for the other end of the overlap in what place, count the number of their overlap part of the grid will be able to calculate the eyepiece microscope micrometer in the case of magnification of the actual magnification.
Specific formula is as follows:
Eyepiece micrometer per frame = (number of overlaps of the table ruler X 10) ÷ number of overlapping frames of the eyepiece ruler. As shown in the figure above, the overlap of the table ruler is 4 frames, and the overlap of the eyepiece micrometer is 10 frames. From this, you can calculate the length of the eyepiece micrometer per grid: (4X10)/10 = 4um.
After determining the length represented by each cell of the eyepiece micrometer, remove the table ruler and use it to determine the actual length of the examined object. Since the biological microscope has several objectives, each objective lens magnification is different, the actual length represented by the eyepiece micrometer in different magnification is different, so in the switching magnification should be recalibrated.
