Calibration slide for microscopes.
The slide features a horizontal micrometer scale with 100 divisions. Each division is 0.01 mm, and the scale is 1 mm long.
The calibration slide (stage micrometer) is used to determine magnification, the microscope's linear field of view, and the division value of scales and eyepiece reticles.
When used with a digital camera, the slide allows you to calibrate the image analysis software for each objective.

Calibrating the image analysis software

Calibration is performed for each objective used for observation. The calibration slide is used to determine the calibration factor for the image analysis software.

Calibration procedure:

1. Secure the calibration slide on the microscope stage.
2. Select the desired objective and set the camera to its maximum resolution.
3. Display a high-contrast image of the scale on the monitor and capture the image.
4. Select "Calibration" mode in the image analysis software.
5. Click to define the maximum visible distance between the first and last scale divisions.
6. Enter the resulting scale size in actual units in the image analysis software.
7. Enter the calibration name, specifying the current objective magnification.
8. Check the result: in "Measurement" mode, measure several divisions on the calibration slide scale in actual units.
9. The image analysis software will save the calibration factor under the selected name. It will then automatically convert the results into the selected units of measurement.

Calibrating the eyepiece scale

The eyepiece scale is calibrated for each objective used for observation. Place the slide on the stage, then focus the microscope on the scale. Rotate the eyepiece in the optical tube until the slide scale and eyepiece scale are aligned parallel to each other.

When using low-magnification objectives, calculate how many eyepiece scale divisions fit within the slide scale.
When using medium- and high-magnification objectives, calculate how many slide divisions fit within the eyepiece scale.

The calculation for each objective is performed using the formula:
E=TL/A, where
E – eyepiece division value
T – stage division value specified on the stage micrometer (0.01 mm)
L – number of stage micrometer divisions
A – number of eyepiece scale divisions.

The corresponding eyepiece scale division values for each objective will thus be recorded.

When measuring an object, first count the number of eyepiece scale divisions covered by the object. Then multiply the result by the scale value previously calculated for the objective in use. The resulting value is the object's true linear size.