A laser rangefinder is an instrument that uses a laser to accurately measure the distance between the lines. The laser rangefinder emits a very thin beam of laser rangefinder light to the target during operation, and the photoelectric element receives the laser beam reflected by the target. interval. If the laser is continuously emitted, the measuring range can reach about 40 kilometers, and the fluorine-lined butterfly valve can operate day and night. If the laser is emitted in pulses, the accuracy is generally low, but for long-distance measurement, it can achieve good relative accuracy. The world's first laser was first developed in 1960 by the American Hughes Aircraft Company scientist Maiman.

The U.S. military soon launched a study of military laser equipment on this basis. In 1961, the first military laser rangefinder passed the US military proof experiment, after which the laser rangefinder soon entered the useful complex. The laser rangefinder is light in weight, small in size, simple in operation, fast and accurate, and its error is only one fifth to several hundredths of other optical rangefinders, so it is widely used in terrain measurement, battlefield measurement, tanks , ranging from aircraft, ships and artillery objects, measuring the height of clouds, aircraft, missiles and satellites. It is an important technical equipment to improve the accuracy of high tanks, aircraft, ships and artillery. Because the price of laser rangefinders has been continuously lowered, the industry has gradually begun to use laser rangefinders. A number of new miniature rangefinders have appeared at home and abroad with the advantages of fast ranging, small size, and reliable functions, which can be widely used in industrial measurement and control, mining, ports and other fields. Mainly classified one-dimensional laser rangefinder is used for distance measurement and positioning; two-dimensional laser rangefinder (Scanning Laser Rangefinder) is used for general measurement, positioning, area monitoring and other fields; three-dimensional laser rangefinder (3D Laser Rangefinder) is used for Three-dimensional general measurement, three-dimensional space positioning and other fields.

1. Must the plane of the object to be measured be straight with the light?

Generally, precise ranging requires the cooperation of a total reflection prism, and the rangefinder used for house measurement is directly measured by the reflection of the lubricated wall, mainly because the distance is relatively close, and the signal strength of the reflected light is large enough. It can be known from this that it must be straight, otherwise the return signal is too weak and the accurate distance will not be obtained.

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

The principle of ranging can basically be attributed to the time required to measure the round-trip target of light, and then calculate the distance D through the speed of light c = 299792458m/s and the atmospheric refraction coefficient n. Because it is difficult to measure the time directly, it is generally to measure the phase of the continuous wave, which is called a phase-measuring rangefinder. Of course, there are also pulsed rangefinders, typically WILD's DI-3000. Note that 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. The construction industry has a handheld laser rangefinder for house measurements that works on the same principle.

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

It is generally possible, and in practical engineering, a thin plastic plate is used as a reflective surface to deal with the serious problem of diffuse reflection.