How to use a laser range finder

A laser range finder is an instrument that uses a laser to accurately measure the distance of a target. The laser range finder emits a very thin laser beam to the target during operation. The photoelectric component receives the laser beam reflected by the target, and the timer measures the time from the transmission to the reception of the laser beam to calculate the distance from the observer to the target. The laser range finder is light in weight, small in size, simple in operation and fast and accurate, and its error is only one-fifth to one-hundredth of the other optical range finder.

If the laser is continuously launched, the measuring range can be up to 40 kilometers, and it can be operated day and night. If the laser is pulsed, the absolute accuracy is generally low, but for long distance measurement, good relative accuracy can be achieved.

Laser is a new technology developed in the 1960s. It is a light that is very pure in color, highly concentrated in energy, and very directional. A laser range finder is an instrument that uses a laser to measure distance. Its principle of action is simple: the distance is determined by measuring the time at which the laser begins to emit and the laser is reflected back from the target. For example, a laser range finder is used to measure the distance of the moon. If the time from the start of the laser to the reflection from the moon is determined to be 2.56 seconds, the one-shot time of the laser to the moon is equal to 1.28 seconds, and the speed of the laser is the speed of light, which is equal to 300,000 kilometers per second. Therefore, the measured distance of the moon from the Earth is the product of the one-way time and the speed of light, that is, 384,000 kilometers. In order to transmit and receive laser light and perform timing, the laser range finder is composed of a laser transmitter, a receiver, a clock frequency oscillator and a distance counter.

The laser range finder can also be used to track the range of artificial satellites, measure the flight height of the aircraft, aim at the target, and perform terrain mapping and surveying.

1. Using the principle of infrared ranging or laser ranging

The principle of ranging can be basically attributed to measuring the time required for the light to travel to and from the target, and then calculating the distance D by the speed of light c = 299792458 m / s and the atmospheric refractive index n. Since the direct measurement time is difficult, it is usually measured the phase of the continuous wave, which is called a phase measuring range finder. Of course, there are also pulsed range finder, typically DI-3000 from WILD.

It should be noted that the phase measurement is not to measure the phase of the infrared or laser, but to measure the phase of the signal modulated on the infrared or laser. The construction industry has a hand-held laser range finder for house measurements that works in the same way.

2. The plane of the object must be perpendicular to the light.

Usually, precision ranging requires a full-reflection prism, and the range finder for house measurement is measured directly by smooth wall reflection, mainly because the distance is relatively close, and the signal intensity reflected back by the light is large enough. It can be known that it must be vertical, otherwise the return signal will be too weak to get the exact distance.

3. The plane of the object can be measured as diffuse reflection

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

4. Ultrasonic ranging accuracy is relatively low and less used.

5. The laser range finder can achieve an accuracy of 1 mm, which is suitable for various high-precision measurement purposes.

Laser range finder is widely used in topographic surveys, battlefield surveys, tanks, aircraft, ships and artillery to measure targets, and measurements of clouds, aircraft, missiles, and satellite heights. It is an important technical equipment to improve the accuracy of high tanks, aircraft, ships and artillery. Due to the continuous downward adjustment of the price of laser range finder, the industry has gradually begun to use laser range finder, which can be widely used in industrial measurement and control, mining, port and other fields.

The hand-held laser range finder has always been the concern and painstaking work of the housing management department in the measurement of housing applications. The housing area map is directly used as the drawing of the title certificate and has legal effect. It is not only directly facing the common people, but also directly related to the economic interests of the people. Therefore, the control of the measurement error of the house is particularly important. According to the past practice, the measurement of the construction area and the use area by the tape measure or the steel tape measure can satisfy the basics. Requirements, however, in the long-distance measurement, the measurement layer is high, the measurement of the hard-to-reach ground has large errors, and there are shortcomings such as labor intensity and complicated work. In today's high-tech development, such primitive and traditional measurement methods have been Obviously not in line with the fast and efficient requirements of today's information society. For this reason, after the introduction of the handheld laser range finder, after several months of practical use, the instrument is generally considered to be particularly suitable for the measurement of buildings with complex structures, middle and high-rise, long-distance houses. Easy to use, accurate measurement data (three millimeter accuracy), improved work efficiency (non-contact measurement), completely discarding a tape measure (or steel tape measure) to measure the house, reducing the measurement error and ensuring the area measurement accuracy. The measurement results make the owners more convinced. Of course, the instrument also has aspects that need to be improved. For example, in the strong sunlight, long-distance target objects are more difficult to see, and accessories such as telescopes are needed. In addition, it is more difficult to calibrate the level bubble for each measurement, and it is best to automatically calibrate. In short, the handheld laser range finder is still popular with us.

The problem that needs attention when using the laser range finder: The laser range finder can not directly measure the human eye to prevent damage to the human body. At the same time, the vibrometer generally does not have a waterproof rangefinder, so it is necessary to pay attention to waterproof. The latest American Rioport laser range finder is mainly suitable for outdoor hunting enthusiasts in the United States, so the advantage of making it is that it can be waterproof and anti-fog, with jungle trees and leaves.

Laser Safety Warnings and Precautions Lasers are high-intensity light source radiating devices. High-power lasers can be used to cut and weld metal materials. Therefore, lasers are seriously harmful to the human body, especially the human eye. Special care must be taken when using them.

Internationally, there is a unified classification and uniform safety warning signs for lasers. The lasers are divided into four categories (Class1~Class4). One type of laser is safe for people, the second type of laser has lighter damage to people, and three types of lasers are more than three types. The laser is seriously harmful to people, and special care should be taken when using it to avoid direct exposure to the human eye.

In the early 1990s, several major companies, such as Europe and the United States, successively produced semiconductor laser diodes for commercial use, which revolutionized the practical application value of lasers. Other types of lasers have greatly limited the application of lasers due to the complexity of the mechanism for generating lasers, their volume, weight, and power consumption. The emergence of semiconductor lasers has solved these problems. As the technology of semiconductor lasers is further matured, the price is gradually reduced, and its application batch and application fields are expanding, and the application prospect is good. The semiconductor laser has small volume, light weight, high reliability, high conversion efficiency, low power consumption, simple driving power supply, direct modulation, simple structure, low price, safe use, and wide application fields. Such as optical storage, laser printing, laser phototypesetting, laser ranging, bar code scanning, industrial detection, test and measurement instruments, laser display, medical instruments, military, security, field detection, construction leveling and marking instruments, laboratory and teaching Demonstration, stage lighting and laser show, laser level and various markings. Some of the unique advantages of semiconductor lasers make them ideal for military applications such as field ranging, gun sighting, shooting simulation systems, blinding, submarine communication guidance, fuzes, security, and more. Some portable weapon device configurations are possible because they can be driven by ordinary batteries.