Angle Measurement; Circular Level - Pentax AP-120 Instrucciones De Uso

To obtain the distance, the reading of upper (A1) and lower (A2)
UK
stadia hairs are used. The difference between the two readings
multiplied by 100 gives the distance from instrument to staff.
Example:
Upper stadia
Lower stadia
The distance from instrument to staff:
D=(1.643 - 1.124) x 100 = 51.9m

4.4.3. Angle measurement

➀
Set up and level the instrument exactly over the point with the
plumb bob.
➁
Align point A, set the circle to read zero.
➂
Turn the telescope, align point B, read the circle. The reading will
be the horizontal angle between A and B. (See Fig. 4).
A
B
5. Testing and adjusting
To ensure the accuracy, adjustment is required before using the
instrument.

5.1. Circular level

➀
Place the instrument on tripod head, turn the foot screws until the
bubble is centered exactly in the middle of the circle.
➁
Rotate the instrument through 180°. If the bubble still lies in the
center, no adjustment required.
A1
A2
1.643m
1.124m
0 350
30 20
Fig. 4