Lasers are widely used in the detection field, with rich technical content, and have a very significant impact on social production and life. Laser ranging is one of the earliest uses of lasers. This is because the laser has many advantages such as strong directionality, high brightness, and good monochromaticity. The basic principle of using the laser transmission time to measure the distance is to determine the target distance by measuring the time required for the laser to travel to and from the target.

Now, in the automatic detection and control method, in addition to ultrasonic sensors and ordinary photoelectric sensors, a new method that can handle long-distance measurement and inspection has been added-transmission time laser distance sensor. It provides flexibility of use for a variety of different occasions, which can include the following:

①Equipment positioning.

② Measure the material level of the material bag.

③ Measure the object distance and object height on the conveyor belt.

④ Measure the log diameter.

⑤Maintain overhead cranes from bumping.

⑥ No error checking occasions.

Laser rangefinders generally use two methods to measure distance: the pulse method and the phase method. The process of pulse method ranging is as follows: the laser emitted by the laser range finder is reflected by the measuring object and then absorbed by the laser range finder, and the laser range finder records the time when the laser goes back and forth. Half of the product of the speed of light and the round-trip time is the distance between the laser rangefinder and the object being measured. The accuracy of the distance measurement by the pulse method is generally about +/- 1 meter. In addition, the measurement blind area of this type of rangefinder is generally about 15 meters.

Four-point introduction to the use of laser rangefinders

(1) Set up the instrument First set up the theodolite on the measuring station, after centering and leveling, install the laser rangefinder mainframe on the theodolite bracket, lock it with the connector fixing screw, insert the battery into the bottom of the mainframe and fasten it. The company advises to place the reflective prism at the key point, center it, level it, and orient the mirror surface toward the host.

(2) Ranging preparation Press the power switch key "PWR" to turn on, the host will self-check and display the original set temperature, air pressure and prism constant value, after the self-check is turned on, it will display "good". If you want to modify the original set value, you can press the "TPC" key to input the temperature, pressure value or prism constant (usually input one by one through the "ENT" key and numeric keys). Under normal conditions, as long as the same type of reflector is used, the prism constant remains unchanged, while the temperature and air pressure may be different for each observation, and need to be reset.

(3) Observe the vertical angle, air temperature and good pressure. Use the theodolite cross wire to aim at the center of the target plate, and measure the vertical angle α. At the same time, observe and record the readings on the temperature and manometer. Observing the vertical angle, air temperature and pressure, the goal is to correct the skew distance, temperature correction and pressure correction of the slant distance measured by the rangefinder, so as to obtain an accurate horizontal distance.

(4) Distance measurement Adjust the main engine sighting axis level adjustment handwheel (or theodolite level fretting screw) and the main engine pitch fretting screw, so that the rangefinder telescope can be accurately aimed at the center of the prism. In the "good" state, accurate aiming can also be determined according to the buzzer movement. The stronger the signal, the bigger the movement and movement. "*" appears. Application fields of laser rangefinders: Laser rangefinders are now widely used in the following fields: electricity, water conservancy, communications, environment, construction, geology, police, firefighting, blasting, sailing, railways, anti-terrorism/military, agriculture , forestry, real estate, leisure/outdoor sports, etc.