Length measurements

The following components are required for length measurements:

Graticule with scale in eyepiece (Fig. 76) or in the slide overlay device (Fig. 74).

Transmitted light stage micrometer for cali- bration.

Before measurement, the micrometer value of the objective/eyepiece combination must be known, i. e. the distance in the specimen that corresponds to a scale interval in the graticule you are using.

Calibration:

Align the stage micrometer and the graticule parallel to one another by rotating the eyepiece and adjust the zero marks of the two scales to exactly the same height (Fig. 76).

Read how many scale divisions of the stage micrometer correspond to how many on the microscope scale (graticule) and divide the two values.

Example:

If 1.220 mm of the stage micrometer corre- sponds to 100 divisions of the measurement scale, the micrometer value is = 1.220 : 100 = 0.0122 mm = 12.2 μm. For extremely low objective magnifications it may be that only part of the measurement scale can be used for calibration.

Important: If using a magnification changer* (DM IRB-SLR and DM IRB/E stands):

Remember to take the additional magnification value into consideration separately instead of extrapolating the micrometer values of the other objectives from the calibration of one objective. Measurement errors may occur if the eyepiece is not pushed into the tube as far as the stop.

Connections for TV cameras and photomicro equipment

All the variants of the Leica DM IRB stand have a photo/TV exit on the left side.

There are also photo/TV exits in the trinocular tubes for vertical adaption of camera systems.

Fig. 76 Graticule scale in the eyepiece (left) and image of the stage micrometer (right)

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Leica DM IRB manual Length measurements, Following components are required for length measurements, Calibration