Sokkia B20, Operator'S Manual, Page: 48 / 60

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7.3 OPTICAL MICROMETER OM5
The detachable optical micrometer OM5 is available for high
precision leveling. Turning the micrometer knob shifts the line
of sight of the telescope vertically a maximum of 10 mm. This
micrometer shift can be displayed in 0.1 mm graduations.
(Minimum sighting distance: 1 m)
Use first order staves with 1 cm graduations or similar preci-
sion staves.
Fig.7.3
1) Mount the OM5 on the telescope of the B2
0
/B2
1
and push
the locking lever fully forward to lock it. (The lens hood
should be retracted.)
2) Turn the micrometer knob to move the line of sight until
the graduation mark on the staff comes to the middle point
between the two wedge reticle lines for an accurate read-
ing, as shown in Fig.7.4.
1