South NTS-960R, Operation Manual

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189
Adjust
1. Take off the protective cover between the optical plummet eyepiece and focusing
knob.
2. Fix the paper. Rotate the instrument and mark the point of the center of optical
plummet which falls on the paper at every 90
°
. As illustrated: Point A, B, C, and D.
3. Draw lines that attach AC and BD and mark the intersection point of the two lines
as O.
4. Adjust the four adjusting screws of the optical plummet with an adjusting pin until
the center mark coincides with Point O.
5. Repeat the inspection and adjusting steps to make the instrument meets the
requirements.
6. Replace the protective cover.
15.9 INSTRUMENT CONSTANT
（
K
）
Instrument constant has been checked up and adjusted in the factory, K=0. It
seldom changes and it is suggested to check one or two times every year. The
inspection should be made on the base line, also can be made according to the
following method.
∙ Check
1. Mount and level the instrument on Point A at a plain field. Use the vertical hair
to mark Point B and Point C with the distance of 50m on the same line, and set the
reflector accurately.
2. After setting temperature and air pressure, measure the horizontal distance of
AB and AC accurately.
3. Set the instrument on Point B and center it accurately, measure the Horizontal
Distance of BC accurately.
4. Then the Instrument Constant can be obtained:
K
＝
AC
－
(AB
＋
BC)
K should be near to 0, If
｜
K
｜＞
5mm, the instrument should be strictly
inspected in the standard baseline site, and adjusted according to the inspection
value.