Leica DM1000 LED manual Measurements with the Microscope, Linear Measurements, Micrometer Value

10. Measurements with the Microscope

10. Measurements with the Microscope

10.1 Linear Measurements

The following are required for linear measure- ments:

-Graticule with scale division* in eyepiece or a digital linear measuring eyepiece*.

-Stage micrometer for calibration.

(→ fig. 50)

Micrometer Value

The micrometer value of the objective-eyepiece combination used must be known before the measurement, i.e. the distance in the specimen that corresponds to the length of a division on the graticule used.

Calibration:

•Align the stage micrometer and the graticule parallel to each other by rotating the eyepiece and adjust the zero marks of both scales to exactly the same height

•Read how many scale divisions of the stage micrometer correpond to how many on the microscope scale (graticule)

•Divide the two values; the result is the micrometer value for the total magnification that has just been used

Example:

If 1.220 mm of the stage micrometer corresponds 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.

Notes:

If using a magnification changer:

Remember to take the additional magnification value* into consideration! We strongly recom- mend you calibrate each objective 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.

Particularly large object structures can also be measured on the stage with the verniers (0.1 mm); the distance to be measured could be calculated from a combined x and y measurement.

Fig. 50

Scale division of the graticule in the eyepiece (left) and image of the stage micrometer (right)

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