Instruction Manual for the DQL-16B Altimeter

Release Date:

2021-06-22

DQL-16B Type altimeter ， Used to measure the height and slope of a target. ， Composed of a liquid-damped altimeter ， Easy to use ， The aluminum housing is robust, impact-resistant, waterproof, and corrosion-resistant. This high-precision degree High-quality instruments ， Fast and accurate measurement ， And it can be measured with one hand. Measure The protractor’s scale is marked in degrees and percentages ( 0-90 °, 0 One 150% ) The scale interval is I degree /1% , as shown in the figure 1。

Feature Overview

Optical focusing

Optical adjustment is performed by rotating the eyepiece with your fingers. festival, Make the engraved lines clear to the eye. ， At the height-measuring stage, keep the eyepiece slit horizontal.

Structure

The altimeter dial is supported by jewel bearings, and all moving parts are immersed in a damping fluid. ， The function of this damping fluid is to quickly return the dial to its zero position, enabling smooth, vibration-free rotation of the dial face.

How to use

People usually read numbers using their right eye. ， Some people find it easier to use their left eye. ， Because there are visual differences. ， It is best to use both eyes simultaneously. Look . Be careful not to block your line of sight with your hand.

Hold the instrument up to your eyes with your hand. ， Let circle The window faces left. ， Adjust the instrument's elevation to aim at the target. eye Mark ， Until the horizontal scale line is aligned with the object being measured. ， Read the scale through the eyepiece. Due to an optical illusion, the horizontal scale lines appear to extend continuously outward toward the object being measured. ， This makes it easy to check whether the horizontal scale line is aligned with the object being measured. ， Enables quick and accurate readings, as shown in the figure. 2。

The left-hand scale displays the slope angle in degrees. ( High-level eye surface )， The right-hand scale indicates the height from the same eye level to the measurement point. ， It is expressed as a percentage of the horizontal distance; the calculation process is illustrated with the following example.

Measure the horizontal distance now. 25m Height of the column ， See the figure. 3， Tilt the instrument until the horizontal level line is aligned with the top of the pole. ， Obtain the reading 48%， Because the horizontal distance is 25m， Then the height of the column is :48% times 25 = 12m ， This value must be added to the height of the eyes above the ground. ， For example 1.6m， The final result is :12+1.6=13.6m ， This is the height of the column. For precise measurement, ， Especially when measuring while standing on a slope. ， Two values need to be measured. ， From an eyepiece to the top of the column ， The other eyepiece is at the base of the column.

If the base of the column is below eye level, the percentage value read must be cumulatively added. For example, as shown in the figure. 4， If the top reading is 41% , the bottom reading is 13% , then the horizontal distance 25m The height of the column is :(41+13)% times 25m = 54% times 25m = 13.5m 。

The trigonometric relationships are: :

H = h × cos a

Among them : H- True or correct altitude

h- Observed altitude

a- Ground slope angle

The correct horizontal distance can also be obtained from the above equation.

Among them : h- Distance measured along the ground

H - Correct horizontal distance

When calculating horizontal distance using ground-measured distances and slope angles, if the slope angle is measured from eye level to the base of the pole, an error will be introduced (because there is a certain vertical distance between the eyes and the ground). ) However, measuring the slope angle directly at ground level is rather cumbersome and inconvenient. To avoid introducing errors, when measuring the slope angle, a visible marker should be set up at eye level on the slope (or a post should be placed). ， Mark the eye-level position. ) , the two measurement lines become parallel; align the eyepiece with this point for measurement, and the correct slope angle is 9 degree . Figure 6 Provide examples to illustrate the two calculation methods.

Method One ： The distance measured along the ground is 25m， Measurement slope The angle is 9° ，

The percentage readings at the top and bottom of the column are, respectively: 29% and 23%

Calculate

29% + 23% = 52%

25m × 52% = 13m

13m × cos9° = 12.8m

Method Two ： Use cos a(a For the slope angle ) Multiply by the ground-measured distance. 25m

cos 9° × 25 m = 24.7 m 24.7 m × (23 + 29)% = 12.8 m

This example illustrates that if the slope angle is 9° The height error at that time was only 2.3% ， If the slope angle is 35° The timing error then reaches 18%。