Stage Micrometer, Calibration Slide with both Metric & English measurements.
A stage micrometer or calibration slide is a glass slide with some scales on it such as millimeter, micrometer or inches. This is normally used to have a precise measurement of acquired images or add a correct scale bar after acquisition on an image for reference purpose.
BICS-0.01M-E Calibration Slide / Stage Micrometer
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 instructions are available here.
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.
The micrometer slides allow you to calibrate your images based on the magnification in use. After calibartion, you will know the actual pixel size and then add a scale bar to your images.
Use any imaging software that comes with your camera, to calibrate your images.