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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.
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 ex-
actly the same height.
• Read how many scale divisions of the stage
micrometer correspond to how many on the
microscope scale (graticule).
• Divide the two values. The result is the mi
-
crometer value for the total magnification that
has just been used.
Example:
If 1.220 mm of the stage micrometer meets 50 increments
of the measuring scale, the micrometer value is = 1.220:50
= 0.0244 mm = 24.4 μm. For objectives with very low mag-
nification, in some cases only a part of the measuring
scale can be used for calibration.
Note:
If using a magnification changer: Remember
to take the additional magnification value into
consideration! We strongly recommend 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 can be calcu
-
lated from a combined x and y measurement.
10. MeasureMents with the Microscope
