Nikon DTM-330, Instruction Manual

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2-8 Face-left/Face-right Measurement
Face-left Measurement: Measurements made with the vertical circle positioned to
the left of the telescope eyepiece
Face-right Measurement: Measurements made with the vertical circle positioned to
the right of the telescope eyepiece
y
Be careful not to catch your finger in the opening between the
instrument’s standard and the telescope when rotating the telescope.
y
Mechanical constant error (except in some special cases such as vertical
axis error) can be effectively cancelled out by averaging the
measurement values obtained in face-left and face-right measurements.
Therefore, both measurement methods should be used whenever
possible.
)
Face-left measurement
Face-right measurement