With the development of science and technology, it seems that most people still don't know about laser rangefinders, and they don't understand laser rangefinders. Some workers even use tape measures to measure distances and use pens to calculate area, volume, and so on. Now I will introduce the principle and use method of laser rangefinder, which can allow workers to work and study with high efficiency and high precision.

A laser rangefinder is an instrument that uses lasers to accurately measure the distance to a target. The laser rangefinder emits a very thin laser beam to the target when it is working, and the photoelectric element receives the laser beam reflected by the target. The timer measures the time from emission to reception of the laser beam, and calculates the distance from the observer to the target.

If the laser is fired continuously, the measuring range can reach about 40 kilometers, and the operation can be carried out day and night. If the laser is pulsed, the absolute accuracy is generally low, but for long-distance measurement, a good relative accuracy can be achieved.

The first laser in the world was first successfully developed in 1960 by Mayman, a scientist at Hughes Aircraft Corporation of the United States. The US military quickly carried out research on military laser devices on this basis. In 1961, the first military laser rangefinder passed the U.S. military demonstration test, after which the laser rangefinder soon entered the practical complex.

The laser rangefinder is light in weight, small in size, simple to operate, fast and accurate, and its error is only one-fifth to one-hundredth of other optical rangefinders, so it is widely used in terrain surveying, battlefield surveying, and tanks. , The distance measurement of aircraft, ships and artillery to the target, the measurement of the height of clouds, aircraft, missiles and artificial satellites. It is an important technical equipment to improve the accuracy of high tanks, aircraft, ships and artillery.

As the price of laser rangefinders continues to drop, the industry has gradually begun to use laser rangefinders. A number of new miniature rangefinders with the advantages of fast ranging, small size, and reliable performance have emerged at home and abroad, which can be widely used in industrial measurement and control, mines, ports and other fields.

The measuring principle and method of laser rangefinder

1. What is the principle of using infrared ranging or laser ranging?

The principle of ranging can basically be attributed to the measurement of the time required for the light to go back and forth to the target, and then the distance D is calculated by the speed of light c =299792458m/s and the atmospheric refraction coefficient n. Because it is difficult to measure time directly, it is usually to measure the phase of continuous wave, which is called a phase measuring rangefinder.

It should be noted that the phase measurement is not to measure the phase of infrared or laser, but to measure the phase of the signal modulated on infrared or laser. There is a hand-held laser rangefinder in the construction industry for house surveying, and its working principle is the same.

2.Does the plane of the measured object have to be perpendicular to the light?

Usually precision ranging requires the cooperation of a total reflection prism, and the rangefinder used for house measurement directly uses the reflection of a smooth wall to measure, mainly because the distance is relatively short, and the signal intensity of the light reflection is large enough. It can be known from this that it must be vertical, otherwise the return signal is too weak and the precise distance cannot be obtained.

3. Is it okay if the plane of the measured object is diffuse reflection?

Usually, it is also possible. In actual engineering, a thin plastic plate is used as a reflecting surface to solve the serious problem of diffuse reflection.

4. Ultrasonic ranging accuracy is relatively low, and it is rarely used now.