Instruction Manual for the DQY-1G Geological Compass

Instruction Manual for the DQY-1G Geological Compass

Product Implementation Standard: Q/HGY06-2020

I. Purpose >>

The DQY-1G geological compass is primarily used for:

1. Measurement of structural attitudes: including strike, dip direction, and dip angle;

2. Topographic surveying: includes determining orientation (i.e., intersection positioning), measuring slope angles, and establishing horizontal planes;

3. Measure the vertical angle.

II. Main Performance >>

1. The damping time of the magnetic needle (the time it takes for the needle to deflect by 90° and then come to rest in its original position) is 30–60 seconds.

2 Reading error: a. The difference between the degree readings before and after the magnetic needle rotates shall not exceed 0.5°;

b. At 0°–180° and 90°–270°, the error caused by eccentricity in the magnetic needle shall not exceed 0.5°;

c. The reading error of the protractor shall not exceed 0.5°.

3. Level sensitivity: a. Long level: 15′ ± 3′ per 2 mm

b. Circular level: 30′±5′/2mm

4. Instrument external dimensions (length × width × height): 85 × 73 × 35 mm

5. Instrument weight: 0.26 kg

III. Principles and Structure >>

1 Principle: This instrument exploits the property of a magnetic object (i.e., a magnetic needle) to align itself in a specific direction along the magnetic meridian. By reading the scale on the dial, the direction of a target relative to the magnetic meridian can be determined. Based on two selected measurement points (or known reference points), the position of another unknown target can be calculated.

2 Structure (refer to the structural schematic diagram)

The instrument consists of an upper cover 6 and a housing 13 joined by a hinge 8, forming the main body of the instrument. The upper cover houses a reflecting mirror 7, which enables the target to be reflected in the mirror. On the exterior of the housing 13 is a long sighting device 1; when used in conjunction with a small sighting device 5, it allows for accurate aiming at the target. Inside the housing are a graduated dial 2 and a magnetic needle 3, which permit direct reading of the target’s azimuth. A circular level 10 indicates the instrument’s horizontal position. A long spirit level 4 and an indicator dial 11 are provided for measuring slope angles, with readings taken directly from the inclination scale on the adjusting knob 12. Switch 9 serves as the magnetic needle braking mechanism. An adjustment shaft for magnetic declination is also provided on the exterior of the housing. This instrument features a compact structure, small size, portability, reliable accuracy, and stable performance.

IV. Instructions for Use >>

(1) Measurement of structural attitudes (including strike, dip direction, and dip angle)

1. Determining the strike: The strike is the direction of the rock vein’s horizontal projection.

Open the instrument’s top cover 6 to its full extent, set the local magnetic declination, and place the instrument’s two long sides against a characteristic (representative) surface of the rock layer. Keep the circular bubble level centered, then read the value indicated by the north pole of the magnetic needle (note that the end wrapped with copper wire is the south pole of the needle); this reading represents the strike of the rock layer.

2. Measure the dip: the direction perpendicular to the plane indicated by the strike.

Place the short side of the base plate beneath the connecting hinge 8, or the back of the top cover, against the characteristic surface of the rock layer, ensuring that the circular spirit level remains centered. The reading indicated by the north pole of the magnetic needle at this point represents the dip direction of the rock layer.

3. Dip angle: the angle between the vertical and the horizontal plane perpendicular to the strike.

Open the top cover 6 to its limit position, ensuring that the instrument’s side is perpendicular to the strike and tightly aligned with the characteristic surface of the rock layer. Adjust the bubble level until it is centered, then read the degree indicated on the dial; this value represents the dip angle of the rock layer.

In practical measurements, only one of the two factors—strike or dip—needs to be measured, since strike and dip are perpendicular to each other (90° apart).

(2) Topographic surveying (including azimuth determination, slope angle measurement, and horizontal line identification)

1. Determining the azimuth: the direction and location of the target; determining the azimuth is also known as intersection positioning.

(1) Measurement method when the target is above the horizon. Hold the instrument firmly in the right hand, with the back of the upper cover facing the observer and the arm kept close to the body to minimize shaking. With the left hand, adjust the long sighting tube and the reflecting mirror; then turn the body until the images of the target and the tip of the long sighting tube are simultaneously reflected in the mirror and bisected by the mirror’s line. Keep the circular bubble level centered, and read the degree indicated by the north pole of the magnetic needle—this is the direction of the target. Using the same procedure, measure the target from another observation point. By measuring the same target from two different points and drawing lines along the measured bearings that intersect at the target, the target’s position can be determined.

(2) Measurement method when the target is below the line of sight (horizontal line). Hold the instrument firmly in the right hand, with the reflecting mirror positioned opposite the observer; keep the arm close to the body to minimize shaking. Use the left hand to adjust the long sighting tube and the upper cover, then turn the body until the target and the tip of the sighting notch are simultaneously reflected in the elliptical aperture of the reflecting mirror and bisected by the mirror’s centerline. Maintain the circular bubble level centered, and read the degree indicated by the south pole of the magnetic needle; this value represents the direction to the target. Follow the same procedure to measure the target from another observation point. By measuring the target from two different points and drawing lines along the measured bearings that intersect at the target, the target’s position can be determined.

2. Slope angle: the angle between the line of sight from the observer to the target and the horizontal plane.

Hold the instrument’s housing and base with your right hand, with the long sighting tube on the observer’s side; ensure the instrument’s plane is vertical to the horizontal, and that the long bubble level is centered at the bottom. With your left hand, adjust the top cover and the long sighting tube so that the target and the aperture of the sighting tip are both bisected by the elliptical line etched on the reflecting mirror. Then, use the middle finger of your right hand to adjust the handle, observing through the reflecting mirror until the long bubble level is centered. The reading indicated on the dial mounted on the handle at this moment is the slope angle of the target. If you are measuring the slope angle of a particular slope, simply open the top cover to its full extent, place the instrument’s side directly against the slope, center the long bubble level, and read the angle—this will be the slope angle of that slope (which is identical to the dip angle in structural measurements).

3. Establish the horizontal line

Rotate the long sighting device until it lies in the same plane as the box face, tilt the top cover to 45°, and ensure that the sighting tip is vertical and parallel to the top cover. Align the indicator with “0”; the line of sight through the sight hole on the sighting tip and the elliptical aperture of the reflecting mirror will then coincide with the horizontal line.

(3) Measuring the Vertical Angle of an Object

Rotate the top cover to its extreme position, then press the side of the instrument firmly against a representative flat surface of the object (such as a drill pipe). Adjust the bubble level until it is centered; the reading indicated by the dial at this point represents the vertical angle of the object.

V. Precautions >>

1. The magnetic needle, the jewel bearing, and the jewel pin are the instrument’s principal components and must be carefully protected to maintain the needle’s sensitivity. When the instrument is not in use, it should be securely closed. Once the instrument is closed, a switch automatically lifts the magnetic needle, disengaging the jewel pin from the jewel bearing to prevent wear on the pin.

2. Do not disassemble any hinges lightly, as this may cause them to loosen and compromise accuracy.

3. Avoid exposing the instrument to high temperatures and direct sunlight as much as possible to prevent air leakage and malfunction of the water bladder.

4. The pivoting parts of the hinge should be regularly lubricated with watch oil to prevent dry friction and breakage.

5. The instrument should be placed in a well-ventilated, dry location, away from magnetic objects.

Harbin Optical Instruments Factory Co., Ltd.

HARBIN OPTICAL INSTRUMENT FACTORY LTD.

ground   Address: Jingwei Third Road, Daoli District, Harbin City 32 Number

Post   Editor: 150010

Electricity   Words: 400-030-0319         0451-84286338      

network   Address: www.hrboptical.com           

E-mail： hopt@hopt.cn