NPZ 1PN91-2, Service Manual

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For example: We know the direction angles of the directions: for the object N.
they are 8-69, for the object N.2 they are 4-37, for the object 3 they are 20 -2.
During checking by these objects, the magnetic azimuths shown in the table 3
were defined.
Table 3
Readings
Numbers of objects
2 3
8-36 4-05 9-88
2 8-34 4-0 9-85
3 8-40 4-07 9-88
Arithmetic average 8-37 4-04 9-86
Define the difference between the average values of the magnetic azimuths
and corresponding direction angles:
Object N.: 8-37 – 8-69 = – 0-32
Object N.2: 4-04 – 4-37 = – 0-33
Object N.3: 9-86 – 20-2 = – 0-35
Define the aiming circle allowance:
The allowance which has been found is valid for the locality free of any
magnetic anomalies, within 20 km from the checking point to the East and
West; within 00 km to the South or North.
4.3 Defining of the angles reading from the reference direction
assigned with regard to the North-South direction
4.3. Aim the observing line of the sighting device at the North with the
help of the aiming circle 4 by turning the handwheel 8 (Figure A.4). Set the
reading 0-00 on the scale 7.
Set the value of the magnetic azimuth angle of the reference direction on
the scale 7 by turning the handwheel 8.
Loosen the scale 7 by turning the handle 6. Set the reading 30-00 on the
scale 7. Fix the scale 7 with the help of the handle 6.
4.4 Measuring of the horizontal angles between two objects
with the help of the reticle
4.4. Rotate the sighting device by turning the handwheel 8 (Figure A.4) for
superposing the vertical line of the cross of the sighting device reticle (the maximum
angle is 0-30) or any vertical line of the sighting device reticle (the angle being from
0-30 to 0-60) with one of the objects between which the angle is being measured.
∆β = -
(32+33+35)
=
-
0
-
33.
3