Instruction Manual for the DQL-2A Pocket Theodolite

DQL-2A Instruction Manual for the Model Pocket Theodolite

Product Implementation Standards :QHGY06-2020

I. Uses

DQL-2A The compact theodolite is primarily used for :

1 , Measure the attitude : Including strike, dip, and dip angle ;

2 , Topographic Survey : Including orientation ( The rendezvous point ) , measure slope angle, establish level ;

3 , Measure verticality ;

4 , Create a topographic map.

II. Main Specifications

1 , Magnetic needle damping time :30-60 seconds

2 , Scale division value: 1 degree

3 , angular value of the circular level vial :30´ scholar 5 ´ /2mm(20℃)

4 1. Instrument external dimensions :77.5×66x20(mm)

5 , Net weight of the instrument :0.2kg

0.2kg

III. Structural Principle

This instrument features a compact design, small footprint, light weight, portability, and simple operation, while also delivering reliable accuracy and stable performance.

This instrument determines the azimuth of a target by reading the magnetic needle against a graduated dial. In addition, it incorporates a plumb-bob-type protractor; when used in conjunction with the slope-angle scale on the steering wheel, it enables the determination of various slope angles of the target.

Instrument top cover (1) and the housing (10) Through the shaft (3) forms the main body of the instrument. A reflecting mirror is mounted on the top cover. (2) , allowing the target to be reflected in the mirror. A magnetic needle is installed inside the casing. (13) and the dial (5) The target’s azimuth can be read directly, and it is also equipped with a steering wheel. (12) , protractor (11) , circular level vial (6) Press the brake button on the back of the instrument body; the protractor allows you to read the target’s various angles from the steering wheel’s tilt scale. A circular level indicates the instrument’s horizontal position. A magnetic needle switch is also mounted on the top of the instrument body. (4) and the aiming tip (9) The front of the housing is equipped with a gear shaft. (8) For adjusting the magnetic declination. The side of the housing is engraved with 60mm The scale ruler is for drawing.

IV. How to use

 1 , Measure the attitude

① Measure the direction:

The strike is the direction of the projection of the vein on the horizontal plane; when measuring the strike, place the instrument’s top cover ( 1 ) Open to the horizontal position, then turn on the switch ( 4 ) Release the magnetic needle and adjust it to the local magnetic declination; then place the long side of the instrument against the characteristic surface of a representative rock layer. After centering the bubble in the circular level, the reading indicated by the north pole of the magnetic needle (with the end wrapped in copper wire serving as the south pole) represents the strike of the rock layer.

② Tendency measurement:

The dip is the direction perpendicular to the plane defined by the strike. To measure the dip, place the short side of the instrument or the back of its top cover against the characteristic surface of the rock layer, center the circular bubble, and the degree indicated by the north pole of the magnetic needle is the dip of the rock layer.

③ Measure the tilt angle:

The dip angle is the angle between the strike-slip plane and the horizontal plane. To measure the dip angle, first open the top cover to the horizontal position, lock the magnetic needle, ensure that the side of the instrument is perpendicular to the strike and tightly aligned with the characteristic surface of the rock layer, and then press the braking button on the back of the housing (it is best to press it in short, intermittent bursts). 2 to 3 (Repeat this step as many times as necessary.) The angle indicated by the protractor on the steering wheel is the dip angle of the rock layer.

Because direction and tendency are mutually 90 Due to the relationship between these factors, in practical measurements it is sufficient to determine only one of the two—strike or dip; in most cases, only the strike needs to be measured.

2 , Topographic Survey

① Determine orientation:

Azimuth determination, also known as intersection positioning, involves determining the direction and location of a target. First, open the instrument’s top cover and release the magnetic needle. Hold the instrument firmly in your right hand, with the mirror facing away from your arm (when the target is below the horizon, the mirror should face your arm) and press it tightly against your body to minimize shaking. Then, use your left hand to adjust the mirror and turn your body until the target is reflected in the mirror and bisected by the mirror’s centerline. At the same time, align the sighting notch with the mirror’s centerline and keep the circular bubble level centered. The degree indicated by the north pole of the magnetic needle at this moment represents the azimuth of the target.

Using the same method, measure the target from the opposite station; the two lines of sight from the two measurements will intersect at a single point, which is the target’s location.

② Slope angle measurement:

The slope angle is the angle between the line connecting the measurement point to the target and the horizontal plane. During measurement, open the top cover to 90 °, lock the magnetic needle, hold the instrument housing with your right hand so that the protractor faces downward, then sight the aiming point, align the line of sight with the target, and finally press the automatic twist button with your right index finger. 2 To 3 Next, the angle indicated by the protractor on the steering wheel is the slope angle of the target.

If the instrument can directly contact the target’s slope, simply press the instrument’s measuring surface firmly against the target’s feature surface. Then, press the lock button. 2 To 3 Next, the angle indicated by the protractor on the steering wheel is the slope angle of the target.

③ Set the horizontal line:

Establishing a horizontal line means determining whether two or more targets lie on the same horizontal plane. During measurement, open the top cover to 90 °, aim at the target by aligning the sight tip with the line of sight, then press the brake lever. 2 To 3 Next, record the reading indicated by the protractor. Then, at the same measurement point, at the same height, and using the same method, measure another target. If the protractor shows the same reading, this indicates that the two targets lie on the same horizontal plane.

3 , Measure verticality:

Open the instrument’s top cover to a horizontal position, lock the magnetic needle, place the instrument’s long side against the object’s feature surface, and press the brake button. 2 To 3 Next, if the protractor indicates 90 ° indicates that the object is vertical.

4 , Create a topographic map:

On the map, place the instrument with the graduated scale against the survey point (or the known target). Rotate the instrument until the degree indicated by the north end of the magnetic needle matches the degree measured on the ground; then draw a straight line along that edge. This line represents the bearing to the surveyed point of the target, and the intersection of two such bearings is the location of the target.

V. Instrument Adjustment and Maintenance:

1. Depending on the region, when it is necessary to adjust the magnetic declination, open the instrument’s top cover to 90 °, place it on the flat plate, observe that the sighting tip is aligned with the mirror line, then insert the adjusting tool into the gear shaft ( 8 ) can then be adjusted (refer to the supplementary table of magnetic declination for certain regions in China).

2 If, after prolonged use, the upper-cover pivot becomes excessively loose due to wear, loosen the two screws on the upper cover, use a adjusting tool to slightly tighten the nuts at both ends of the pivot, and then align the upper cover with the housing. Finally, tighten the two screws on the upper cover.

If necessary, remove the top cover and the nuts at both ends of the shaft, pull out the bushings at both ends, apply an appropriate amount of grease to the chamfers in the shaft holes, and then reassemble.

3 , switch ( 4 ) The braking mechanism is locked by a magnetic needle; both locking and releasing the magnetic needle must be performed by rotating in a clockwise direction to prevent thread loosening. When the device is not in operation, the magnetic needle should be locked to avoid wear on the spindle tip.

4 The instrument should be protected as much as possible from impacts and contamination, and shielded from high temperatures, direct sunlight, and rainwater to prevent air leakage in the water bath and degradation of the mirror coating, which could compromise the instrument’s performance and accuracy.

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

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