The microscope slide is made of optical glass, has several circles with different diameters (1.5 mm, 0.6 mm, 0.15 mm and 0.07 mm) and has a 1-millimetre-long marking divided into 100 graduations of 0.01 millimetres each.
A calibration slide is necessary to improve measurement accuracy when using camera software. Calibration is performed individually for each lens.
How to use the calibration slide:
- Secure the slide to the microscope stage.
- Rotate the revolver to select the desired lens.
- Take a photo of the slide.
- Select the calibration mode in the image analysis program, point the mouse at the maximum visible distance and then enter the resulting value in real units.
- Enter the name of the calibration and check the values.
- If everything has been done correctly, the programme will remember the correction factor and automatically convert the values into the desired units of measurement in future.
Calibration of the image analysis software
Calibration is performed individually for each objective used for observations. The calibration slide is used to determine the calibration factor for the image analysis software.
- Secure the calibration slide to the microscope stage.
- Select the desired lens and set the maximum camera resolution.
- Create a contrast image of the slide on the screen and capture the image.
- Select the "Calibration" mode in the image analysis software.
- Click with the mouse to define the maximum visible distance between the first and last divisions of the scale.
- Enter the resulting scale size in real units into the image analysis software.
- Enter the calibration name by specifying the current lens magnification.
- Check the result: In "Measurement" mode, measure a few divisions of the scales on the calibration slide in real units.
- The image analysis software saves the calibration factor under the selected name. The results are then automatically converted to the selected units of measurement.
Calibration of the eyepiece scale
The eyepiece scale is calibrated individually for each lens used for observations. Place the slide on the microscope stage and focus the microscope on the scale. The eyepiece should be rotated in the eyepiece tube until the scales of the slide and the eyepiece are parallel to each other.
- If you are using low-magnification lenses, you should calculate how many divisions of the eyepiece scale fit into the scale of the slide.
- If you are using medium and high magnification lenses, you should calculate how many divisions of the slide fit into the scale of the eyepiece.
The calculation for each lens is made using the following formula:
Е=ТL/A
where:
- E – eyepiece division value
- Т – division value indicated on the slide (0.01 mm)
- L – number of divisions of the slide micrometer
- А – number of divisions on the eyepiece scale.
The resulting values for the division of the eyepiece scale for each lens are recorded.
When measuring an object, first count the number of divisions of the eyepiece scale that cover the object. The result is multiplied by the scale value previously calculated for the selected objective. The resulting value is the true dimension of the object.
