ADA INSTRUMENTS PROF X2, Operating Manual

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MEASUREMENT FOUNDATION
Levelling with the tubular level: Turn the alidade of theodolite first in order to make the tubular level parallel to the line
connecting the centers of any two foot screws (Fig. 5A), and at the same time, turn the two foot screws to enable the bubble to
position itself in the middle of the tubular level. Then turn the alidade 90° (Fig. 5B) and also turn the third foot screw to make the
bubble move to the middle of the level. Repeat the above described procedure several times so that the offset of the bubble
doesn't exceed the allowance for whatever position the alidade is turned.
4. Mounting the instrument properly over the measuring point.
Use an optical plummet to enable the center of the vertical axis of the theodolite to be directly over the plummet line of measuring
point. When the optical plummet is used, pull out its visual lens and turn it so that the measuring point is distinctly imaged on the
graduated plate. If the center of the measuring point is not in the center of the graduated plate, loosen the central screw of the
tripod. Then tighten the central screw of the tripod, and check the levelling of the instrument. Turn the alidade 180° and repeat
the above described procedure.
5. Illumination
Turning the position of the light reflection mirror (11) properly will result in a bright illumination of the graduated circle.
Fig.5A Fig.5B
PROF
X2
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X2