Individual Spta set

1- Rechargeable battery 10D-0,55С-1; 2 - Fuse link VP1-1 1,0А 250 V; 3 - Pencil; 4 - Sealing ring; 5 - Eye shield; 6 - Framed lens; 7 - Cloth; 8 - Eraser; 9 - Wrench; 10 - Coordinate

converter; 11 - Charging device; 12 – Protection device; 13 - Indicating silica gel; 14…18 - Cables; 19 - Membrane; 20, 21 - Cover; 22 - Diaphragm; 23 - Brush No. 7 (made of synthetic fibre)

Fig. 6

Add 60.00 mils to the first value if it is exceeded by the second. During the magnetic orientation of the rangefinder, the angles read off the azimuth dial are the magnetic azimuth values (bearings) of the target (or reference object). You should count the magnetic azimuth correction (see 7.5.3.).

For better precision, take 3 or 4 angle measurements to calculate the mean value. After each measurement of the magnetic azimuth value (bearing), destroy the rangefinder orientation and aim it again.

An azimuth or magnetic azimuth measuring under 0.80 mils may be read off the reticle with a maximum accuracy of 0.05 mils (small division value of the reticle is 0.05 mils, large division value is 0.10 mils).

8.6.To measure vertical and elevation angles, proceed as follows:

- Align the horizontal mark of the rangefinder reticle with the upper object;

- Read the vertical angle scale using the wheel and note down the value;

- Rotate the azimuth and elevation knobs to align the horizontal mark of the reticle with the lower object and read the scale again;

- Determine the vertical angle by subtracting the smaller value from the greater one if both have the same sign (are of the same color), or by adding them, if the signs are opposite.

The elevation is measured with reference to the Binocular axis of the rangefinder. Hence, the rangefinder should be thoroughly levelled before taking the elevation measurements.