Instruction Manual for the DQL-6 Type 1937 Compass

Release Date:

2021-10-28

DQL-6 Type 1937 Compass

COMPASS MODEL DQL-6

Instruction Manual

Harbin Optical Instruments Factory Co., Ltd.

HARBIN OPTICAL INSTRUMENT FACTORY LTD

eye Record

Schematic diagram of the Type 97 compass ……………………………………………………………..1

I. Uses …………………………………………………………………………..3

II. Structure and Performance ……………………………………………………………….…3

III. Instructions for Use ……………………………………………………………………4

IV. Maintenance and Upkeep ……………………………………………………………………9

V. Complete Instrument Set …………………………………………………………………….9

VI. Appendix 1: Conversion Table Between Mil Units and Degrees ……………………………………………10

VII. Appendix II: Difference Between Two Measurements of Instrument Azimuth Readings ……………………………… 11

VIII. Appendix 3: Altimeter ……………………………………………………………12

IX. Appendix 4: Magnetic Declination in Major and Medium-Sized Cities of China ……………………………………… 13

I. Uses
Type 97 Compass It consists of an azimuth-measuring unit, a distance-estimation device, an elevation-angle-measuring unit, a range-measuring unit, and a coordinate scale, among others, and is capable of determining azimuth, distance, elevation angle, map distance, coordinates, and drawing simple maps. Instrument It is coated with luminous markings for use during nighttime operations.
II. Structure and Performance

1. Azimuth measurement mechanism:
It consists of a compass, an azimuth table (also known as a true-azimuth table), a reverse-azimuth table, the rear sight, and the front sight. The outer ring of the azimuth scale is 360° Division system, minimum scale value 2° ; the inner circle is 60-00 Mil-based division system, minimum scale value 0-20 Mil. The conversion between mils and degrees is shown in Table 1.

Measurement accuracy: ±0-10 Mil, ±1° 。
2. Distance estimator:
    It consists of the rear sight and front sight. The angle between the two tips of the front sight and the central line of the rear sight is 1-00 Mil, the length between the two tips is 12.34 millimeters, the length between the rear sight and the front sight is 123.4 Millimeters, that is, the components 10:1 Proportional range estimator.
The measurement accuracy is 5% 。
3. Pitch angle measurement mechanism:
    It consists of an angle dial, a protractor pendulum, a level mirror, and other components, with a measurement range of ±90° , measurement accuracy ±2.5 ° 。
4. Mileage Measurement Agency:
    It consists of an odometer wheel, an odometer, an odometer needle, and a gear train, among other components. Odometers include: 1:100,000 ； 1:50,000 ； 1:25,000 Three scale divisions, in kilometers, with measurement accuracy 1% 。
5. Coordinate scale:
    It consists of a long ruler with one side perpendicular to two shorter rulers; the long ruler 120 Millimeter, short ruler 25 Millimeters, measurement accuracy ±0.5 Millimeter.

6. Instrument external dimensions (length × width × height): 69 times 65 times 26.5 （ mm )

7. Instrument weight: 0.149kg
III. Instructions for Use
1. Measure the azimuth:
    Expand Instrument , rotate the azimuth frame so that the azimuth glass on ( N ) The character is aligned correctly with the direction indicator, supported flat by the left hand. Instrument , put down the reverse-character sign (make sure it is placed flat and properly), and tilt the level mirror. 45° , aim at the target with one eye through the front and rear sights, and view the magnetic needle reflected in the front sight. N On the azimuth table of the polarized counter-azimuth chart, one can first read the target azimuth, and then use the right hand to rotate the azimuth frame so that the azimuth glass’s ( N ) Characters and the Magnetic Needle N Extreme alignment; at this point, the direction indicator and the azimuth glass ( N The angle formed by the two letters is the target azimuth (measured in a clockwise direction).
     A hook is provided at the zero mark on the side scale to facilitate plotting operations; during plotting, a tally-board is used.
     Open Instrument , calibrate the map (map calibration is optional during distance measurement), insert a pin at the reference point on the map, hang the hook on the pin, and rotate. Instrument By aligning the side edge of the protractor with the target point, the azimuth from the reference point to the target point can be read directly.
2. Calibration Map:
    Expand Compass instrument , rotate the azimuth frame so that the ( on the azimuth frame N ) Align the letter with the direction indicator (taking magnetic declination correction into account), and then Instrument Place the map flat, with the sight end pointing toward the map’s true north, so that the long edge of the coordinate scale is tangent to the map’s magnetic meridian. Then rotate the map until the N pole of the magnetic needle aligns with the “N” mark on the azimuth plate; at this point, the map has been properly oriented.

3. Determine the marching direction toward the concealed target:
Expand Instrument On the map, align the surveying ruler so that it passes through your current position and the marching objective; the direction indicator will then point in the intended direction of travel. Rotate the azimuth frame until the (S, N) directions on the azimuth glass match the (S, N) directions on the map, then record the azimuth reading indicated by the direction indicator, and with your face toward the direction indicator, pick up Instrument Rotate your body until the N pole of the magnetic needle aligns with the letter “N” on the azimuth glass. At this point, align the front sight and rear aperture so that they are in line with the target ahead. Any objects along this alignment—such as groves of trees or buildings—can serve as auxiliary landmarks to help determine your marching direction. Once you have identified these auxiliary landmarks, proceed in the indicated direction. Instrument Close the compass and place it in your pocket, but do not rotate the azimuth dial. Once you reach the auxiliary target, locate a new auxiliary target and continue advancing until you reach your final destination, checking the bearing readings frequently along the way.
4. Given the interval between targets, estimate the distance from the target to the standing point:
① Aim at the target by aligning the front and rear sights so that the target’s width spans a certain number of divisions between the two sight blades; then estimate the target’s distance using the 10:1 rule.
Distance to the target (m) = Target interval width (m) × 10 / Number of times the target interval spans the width between the two tips of the iron sights
Example: There is a road ahead that runs parallel to our position; determine the distance between the road and the position. (See Figure 1.) Along the road there are utility poles spaced 50 meters apart. Using a range estimator, it is measured that five poles lie between the two extreme points on the left and right, meaning that the interval between any two adjacent poles accounts for one-fourth of the distance between the two extreme points. According to the proportion formula, we obtain:
Distance between the highway and the position = 50 × 10 × 4 = 2,000 meters

② Determining the distance to the target using auxiliary points
Aim the rear and front sights at the target, rotate the azimuth dial until the letter “N” aligns with the magnetic needle’s north pole, and record the azimuth reading indicated by the direction indicator. Then turn left or right by a right angle (i.e., by 15°00′ relative to the original azimuth reading) to locate an auxiliary point, and use pacing or another method to measure the distance from the auxiliary point to your standing position. At the auxiliary point, again use Instrument Align the front and rear sights with the original target, then rotate the azimuth frame so that the letter “N” is aligned with the north pole of the magnetic needle, and record the reading indicated by the direction indicator. Based on the difference between the two azimuth readings and the distance from the station to the auxiliary point, consult Appendix Table 2 to determine the distance to the target. If the difference between the two azimuth readings is between 7° and 50° (i.e., 45°), then the distance to the target is equal to the distance from the station to the auxiliary point.
5. Measure the pitch angle:
Place the buttstock face down and aim at the target using the rear sight and front sight, reading the elevation angle reflected in the front-sight window; or set the buttstock upright on a flat surface and measure the inclination angle of that surface.
6. Measurement height:

Use a map and an altimeter (Appendix 3) to measure elevation. Determine the horizontal distance from the observation point to the target on the map, then measure the vertical angle of depression with the instrument. Consult the altimeter to obtain the elevation, or calculate it using trigonometric functions.

Example: Find the height from the base to the summit of the mountain. (See Figure 2.)

According to the map, the horizontal distance between the summit and the observation point is 100 meters. Using an instrument, the zenith angle to the summit is measured as 40°. Consulting the elevation table (Appendix Table 3) at the 100-meter mark for a 40° angle yields an elevation of 83.91 meters.

7. Measure the distance between any two points on the map:

① Measure the straight-line distance using a coordinate scale.

For maps at different scales, the calculation formulas for the side length of the square grid and the corresponding ground distance are as follows:

1:25,000 map: Distance = (measured length in millimeters / 4) × 100 (meters)

1:50,000 map: Distance = (measured length in millimeters / 2) × 100 (meters)

1:100,000 map: Distance = Measured millimeter value × 100 (meters)

② Use the mileage mechanism Measure Quantity.

Open the protective cover, rotate the odometer wheel until the odometer needle reads zero; then roll the odometer wheel along the route from Point A to Point B (Note: the odometer wheel must not slip, and the odometer needle should rotate in a clockwise direction). The reading indicated by the odometer needle is the map distance between Points A and B on the corresponding scale map.
Example: Measuring the marching distance between locations A and B along a certain highway (if the map scale is 1:50,000 ). Using the method described above, roll the odometer wheel from location A to location B; then observe 1:50,000 The reading on the odometer scale’s graduated circles, if the odometer needle indicates: 25 then the distance between locations A and B on that highway is 25 Kilometers.
8. Magnetic Declination Measurement:
① The geographic North and South Poles do not coincide exactly with the Earth’s true north–south axis; consequently, the direction indicated by a magnetic compass deviates from true north–south. This deviation is known as magnetic declination, and its magnitude varies from place to place (see Appendix Table 4). When high precision is not required, the direction indicated by the magnetic needle may be taken as approximately true north; however, when precise measurements are necessary, one should first consult a table of local magnetic declination and then, based on the instrument reading, calculate the true north–south direction.
When using the instrument in Harbin, refer to Appendix Table 4, which shows that the magnetic declination in Harbin is 9°51' (W ) , which means that in Harbin, the magnetic needle points to the west of true north. 9°51' the place.
② Method for determining magnetic declination at any location.
On a clear night, unfold Instrument , rotate the azimuth frame so that the letter “N” on the azimuth glass is directly aligned with the direction indicator. Use the rear sight, front sight, level sight, and luminous markers to align with the North Star; without changing the direction of the compass, proceed to Instrument Place it flat; the reading indicated by the north pole of the magnetic needle at this moment is the local magnetic declination.

IV. Maintenance and Upkeep
1. Use and Placement Instrument Avoid placing the compass near ferromagnetic objects, high-voltage power lines, and electromagnetic devices to prevent measurement errors and reduced compass sensitivity.
2. When not in use, store in a well-ventilated, dry place to prevent mold.
3. Do not bend the level mirror or the inverted-character sign holder, as this may compromise their accuracy.
4. When any surface becomes stained or soiled, gently wipe it with a soft cloth to maintain its smooth, glossy finish.
V. Instrument Full set
1. One leather box 2. Instrument 1. One 3. One instruction manual 4. One piece of velvet cloth 5. One ribbon