Product Detail:

Service Instruction for Compass

1.Service Instruction for Compass

Compass Type Y/JBZ97 is composed of coordinate rulers, mechanisms for azimuth, pitch angle (slope), map/real distances, etc. It can measure azimuth,pitch angle (slope), real/map distances and map coordinate, as well as draw simple maps based on measurements.

2.Azimuth Measuring Mechanism 

It consists of magnetic needle system, azimuth dial, counter-clockwise digital azimuth dial (which would be clockwise as viewed from reflective mirror), sight port and head, etc. Full graduation of azimuth is 360° for outer circle and 6000 mil for inner circle.

Procedures to measure azimuth angles in the open is as following: first open the compass, lay the counter-clockwise digital azimuth dial flat; then turn the reflective mirror to 45", and observe the azimuth angle from the mirror. The graduation pointed by the magnetic needle“N” (north) pole is read as azimuth angle. 

3.Distance Measuring Mechanism

It is a simple scaled distance measuring mechanism which measures distance by three sharp angles formed between sight port and sight head (see figures on the left). The length between the sight port and the middle sharp angle would be 10 x A if taking the length between the sharp angles on each side as A, i.e., the scale is 10:1.

Suppose the real width of B (assumed target to be measured) is 5m, and let it just sits between the sharp angles’ vertexes on each side, then the distance between the target and the measurer shuold be:10 x 5 =50m. 

4.Slope Measuring Mechanism

It includes slope dial, slope pendulum and reflective mirror. The measuring range is ±90o

Hold the compass as showed in the left figure, and aim at the target through sight port and head, then the slope grade from the target to the standing point could be read from the reflective mirror. 

The slope measurement could also be used to do simple level calibration.

5.Map Distance Measuring Mechanism

It is composed of rolling wheel,distance dial and pointer ,and is applicable to maps of-three different scales:1:10000, 1:50000, 1:25000.Measuring unit is kilometer.

First roll the wheel and let the pointer point to “0” , then put the compass on the map with the wheel sitting at the starting point (as shown in the left figure), and roll it along the designated route on the map until reach destination.The graduation pointed by the pointer is the map distance in kilometer.

6.Coordinate Rule

It consists of one long ruler(120mm) and two short rulers (25mm), perpendicular to each other.

Put the compass on the map with the long ruler parallel to the latitude while the short rulers parallel to the longitude (as shown in the left figure). Thus the detailed coodinate of the destination could be measured. Moreover, a simple map could be draw with a ruler, and the straight distance between two points on the map could be measured directly as:

7.Maintenance

The compass must be kept away from ferromagnetic materials, high-voltage power cables and electromagnetic units either in use or in storage to avoid error or low sensitivity.

The compass shoule be stored in dry environment with good ventilation to avoid mildewing.

The reflective mirror and the digital azimuth dial should not be distorted of bent to avoid low accuracy.

White flannel could be used to slightly wipe contaminated surface(s) to keep clean and bright. 

8.Product Kit