Geological compass pointer, geological compass reads east and west units to see which needle

The compass pointer is tilted up and down greatly, which affects the use, so it is necessary to adjust it. Pry open the steel ring with a screwdriver and adjust the copper wire on the pointer and it's OK.

This is a normal phenomenon, to control the compass pointer does not tilt up and down, there is a button on the edge of the surface of the compass, and the button will not move if you press this button.

If you feel that releasing the pointer after holding it down does not revert, you can rotate the button appropriately until the pointer can swing smoothly and tilt up and down.

When you first buy it, if it is flat, after a period of time, there are high and low, which shows that after the adjustment of the loss of magnetism, there is also accuracy at all, and you should consider the pure problem of the purchase The landlord has no picture.

I can't say, for example, the traditional compass, some geographers think that the things of the ancients will never fade.

A compass often takes generations to find out where the problem is, think about how terrible it is, generations.

The traditional compass has a life of about 1 or 2 years, and it will have to readjust the seabed, and the question is, how do you know?

Whether your own things are biased to the left or to the right is a simple question, as long as there is precision.

The permanent magnet master disk can adjust the compass arbitrarily and the recommended three-by-one automatic compass can be corrected by all.

Traditional compass precision is not covered.

If you can't indicate the direction correctly, you can open the copper wire loop on the pointer and adjust the position a little.

Just take it apart and pinch off the coil or adjust the coil position.

Study hard and make progress every day.

It's generally the north needle, but ... Hehe, are you a geology major?

Hello, dear, very happy with your question, the use of the geocompass in the southern latitude region is as follows:1Hit Sun Sui to open the compass and put it on the bridge Kai Sakura where you want to measure, making sure the compass is on a level plane.

2.Turn on the power, the compass will automatically start the measurement, it usually takes about a minute, waiting for the measurement to be completed. 3.

The compass displays the geographic coordinates of the measurements, including longitude, latitude, and altitude information. 4.If you need to record it, you can record this information in a notebook, or take a photo directly to record the information on the compass.

5.When you're done taking measurements, remember to turn off the power and put the compass away from moisture, damage, or outside interference.

The geological compass is one of the three traditional pieces in field geological investigation, and the use of geological compass to measure the occurrence (trend, inclination, dip) of rock layers and faults is the basic skill of geological investigation. Here's how:

First, use a geological compass to measure the course of rock formations (or faults). When measuring the direction of the rock layer, one of the edges of the long side of the compass (the edge marked with n-s parallel to the compass) is close to the plane, and then slowly rotate the compass (note: in the process of rotation, any point of the edge of the compass close to the layer can not leave the plane), so that the bubble of the circular level is centered, and the magnetic needle stops swinging, and then the reading pointed by the magnetic needle is the direction of the rock formation.

It is possible to read either the north or south of the magnet, as the strike of the rock formation extends in both directions, with a difference of 180°. For example, the strike of the rock formation is 60° or 240°.

Second, use a geological compass to measure the tendency of rocks. When measuring the inclination, use the north end of the compass to point to the direction of inclination of the plane, so that the short side of the compass (i.e. the S edge) is close to the plane, flattened, and rotate the compass, the rotation method and principle are the same as above, and the reading of the north needle is the desired tendency. The inclination has only one pointing and can only be expressed by a numerical value, e.g. the inclination of a rock formation is 150°.

If it is difficult to measure at the upper level of the rock formation, it can also be measured on the bottom surface of the rock formation, still using a long sight mark to point to the direction of the rock layer's inclination, and the north end of the compass is close to the bottom surface, and the north arrow can be read. If there is an obstacle in reading the north needle when measuring the bottom surface, the south end of the compass is close to the bottom of the rock formation, and the S needle can also be read.

Third, use a geological compass to measure the inclination angle of the rock. When measuring the inclination angle, the compass is erected, its long side is close to the layer, and it is perpendicular to the direction line, and the compass is tossed with the middle finger to make the level (long level) bubble on the inclinometer centered, and the reading of the semicircular dial pointed by the vernier on the inclinometer is the inclination. The dip angle varies between 0 and 90°, for example, the dip angle of a rock formation is 35°.

Fourth, precautions. In the field, the determination of occurrence factors is often only necessary to measure the inclination and dip of the rock strata and all structural planes, and record them. Format of the record:

The occurrence of the rock formation is 150° 35°, the former indicates the inclination, and the latter indicates the dip angle of the rock formation. Since the strike and inclination differ by 90°, the inclination plus or minus 90° is the strike, and the strike of the above rock strata is 60° or 240°. This is also the reason why trends are generally not recorded.

The strike is recorded only when the dip of the rock layer is close to upright.

When measuring the occurrence of rock strata in the field, it must be measured on the outcrop of the rock formation, not on the rolling stone, so it is necessary to distinguish between the outcrop and the rolling stone. The main way to distinguish between outcrops and rolling stones is to observe and recourse, and to be good at judgment.

In addition, if the surface of the rock layer to be measured is uneven, the record book can be placed flat on the rock layer as a layer to improve the accuracy and representativeness of the measurement. If the rock layer is very incomplete, then it is necessary to find the section of the rock layer, find the three points belonging to the same layer (generally easy to find in the two intersecting sections), and then use the record book to connect the three points into a plane (equivalent to the rock layer), then measure the plane of the record book.

1.Determination of the strike of rock formations.

The trend of the rock layer is the direction of the intersection of the rock layer and the horizontal plane, that is, the extension direction of the horizontal line at any height of the rock layer.

When measuring, the long side of the compass is close to the layer, and then the compass is rotated so that the blister of the chassis level is centered, and the scale pointed by the pointer is the direction of the rock formation.

Because the strike represents the direction of a straight line, it can extend on both sides, and the compass or north arrow reading is the direction of the two ends of the straight line, such as NE30 degrees and SW210 degrees can represent the direction of the rock formation.

2.Determination of the tendency of rock formations.

Rock stratigraphic inclination - refers to the projection of the maximum downward inclination direction line of the rock stratum on the horizontal plane, which is always perpendicular to the trend of the rock strata.

When measuring, point the north end of the compass or the joint plate in the direction of inclination, and the south end of the compass is close to the layer and rotate the compass so that the blister of the chassis level is centered, and the scale pointed by the north arrow is the tendency of the rock formation.

If it is difficult to measure on the top surface of the rock formation, you can also measure on the bottom surface of the rock formation and still use the object plate to point to the inclined direction of the rock formation, the north end of the compass is close to the bottom surface, and the north arrow can be read.

3 Determination of dip angles of rock formations.

The dip angle of the rock layer is the maximum angle between the rock layer and the imaginary horizontal plane, that is, the true dip angle, which is measured along the true inclination direction of the rock layer, and the dip angle measured along the other directions is the apparent dip angle. The apparent dip angle is always smaller than the true dip angle, that is to say, the angle between the true inclination line and the horizontal plane on the rock layer is the true inclination angle, and the angle between the apparent inclination line and the horizontal plane on the plane is the apparent inclination angle. In the field, it is very important to distinguish the true inclination direction of the layer, it is always perpendicular to the direction, and in addition, small stones can be used to make it roll or drip water on the plane to make it flow on the plane, and the direction of this rolling or flow is the true inclination direction of the plane.

When measuring, the compass is upright, and the long side is leaning against the true inclination line of the rock formation, moving the compass left and right along the layer, and moving the movable wrench at the bottom of the compass with the middle finger to center the blister of the inclination level, and read the maximum reading pointed by the middle tip of the crest crest, which is the true inclination angle of the rock formation.

The occurrence of rock formations is usually recorded in the following way:

If the azimuth is recorded, if the strike of a certain rock formation is measured to be 3100, the inclination is 2200

Inclination 350, then recorded as NW3100 SW 350 or 3100 SW 350 or 2200 350.

When measuring the occurrence of rock strata in the field, it is necessary to measure the outcrop of the rock formation, and it cannot be measured on the turning stone (rolling stone), so it is necessary to distinguish between the outcrop and the rolling stone. To distinguish between outcrops and rolling stones, the main thing is to observe and pursue more and be good at judgment.

When measuring the occurrence of a rock layer, if the rock layer is uneven, the notebook can be placed flat on the rock layer as a layer for measurement.

When measuring the inclination, read the value of the middle line of the level on the dial in the compass, do not read any needle, and only read the south or north needle when measuring the tendency.

The geological compass is mainly used to measure inclination, dip (slope angle), and strike (azimuth). It is also possible to perform intersection points with low intensive reading. When measuring the occurrence of a geological body, it is necessary to measure the direction first, and the method is that the long side of the compass is close to the geological body.

How to use:

1) Measurement of occurrence (including trend, inclination, and inclination).

1. Trend measurement: Trend is the direction of the projection of the on the horizontal.

The upper cover (6) of the instrument is opened to the limit position, the magnetic declination angle of the area is adjusted, the two long sides of the instrument are leaned against the characteristic surface (representative surface) of the rock formation, and the round blister is kept in the center, then the degree indicated by the north pole of the magnetic needle is the direction of the rock formation.

2. Measure tendency: the direction perpendicular to the direction of the indicated surface.

If the short side of the chassis at the bottom of the joint hinge (8) or the back of the upper cover are used to stabilize the characteristic surface of the rock formation, and the round blister is kept centered, then the degree indicated by the north pole of the magnetic needle is the tendency of the rock formation.

3. Dip angle: the angle perpendicular to the angle of the horizontal plane of the strike.

Open the upper cover (6) to the limit position, the side of the instrument is perpendicular to the strike and adheres to the characteristic surface of the rock formation, the elongated blister is centered, and the degree of the steering wheel pointed to by the indicator is read, which is the inclination angle of the rock formation.

In the actual measurement, only one of the two factors of trend and tendency needs to be measured, because the trend and tendency are 90° related to each other.

2) Rough topographic survey (including azimuth, slope angle, and horizontal line).

1. Orientation: The direction and position of the target. The fixed direction is also called the intersection point.

The measurement method when the target is above the line of sight (horizontal line).

Hold the instrument with the right hand, the back of the upper cover facing the observer, the arm close to the body to reduce shaking, the left hand adjusts the telescope and the reflector, and rotates the body so that the target and the image of the long illumination point are reflected in the mirror at the same time, and is bisected by the mirror line, keeping the round blister centered, then read the degree indicated by the north pole of the magnetic needle, which is the direction of the target.

According to the same method, the target is measured at another measuring point, so that the measurement of the same target by two measuring points obtains the degree measured along the two lines, intersects the target, and the position of the target is obtained.