Daily maintenance and principle of laser rangefinder
Maintenance of optical rangefinder:
(1) always check the appearance of the instrument and remove the dust, grease and mildew on the surface in time.
② Soft dry cloth should be used when cleaning eyepiece, objective lens or laser emission window. It is forbidden to use hard objects to scribe, so as not to damage the optical performance.
③ This machine is a high-precision instrument integrating optics, mechanics and electricity, so it should be handled with care, and it is forbidden to squeeze or fall from a height to avoid damaging the instrument.
Problems needing attention when using: Laser rangefinder can't be aimed at human eyes for direct measurement to prevent harm to human body. At the same time, the general laser range finder of vibration instrument does not have waterproof function, so it is necessary to pay attention to waterproof. Therefore, the advantage of the production place is that it can be waterproof and fog-proof, and it is equipped with jungle trees and leaves painted.
The laser does not have the function of anti-falling, so the laser rangefinder can easily break the light emitter.
principle
1. The measurable object plane is diffuse reflection.
Usually, it is also possible. In practical engineering, thin plastic plates will be used as reflecting surfaces to solve the serious problem of diffuse reflection.
2. Using the principle of infrared ranging or laser ranging.
The principle of ranging can basically be summed up as measuring the time required for light to travel to and from the target, and then calculating 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 usually to measure the phase of continuous wave, which is called phase measuring rangefinder. Of course, there are also pulse rangefinders, typically the DI-3000 of WILD.
It should be noted that phase measurement is not to measure the phase of infrared or laser light, but to measure the phase of signal modulated on infrared or laser light. There is a hand-held laser rangefinder in the construction industry, which is used for housing measurement, and its working principle is the same as this.
3. The accuracy of laser rangefinder can reach 1 mm error, which is suitable for various high-precision measurement purposes.
Problems needing attention when using laser rangefinder: laser rangefinder can't be aimed at human eyes for direct measurement to prevent harm to human body. At the same time, the general laser range finder of vibration instrument does not have waterproof function, so it is necessary to pay attention to waterproof. The American Leopold laser rangefinder is mainly suitable for outdoor shou hunters in the United States, so the advantage of its production is that it can be waterproof and fog-proof, and it is equipped with painted branches and leaves of jungle trees.
4. The plane of the measured object must be perpendicular to the light.
Usually, precision distance measurement needs the cooperation of total reflection prism, while the distance meter used for house measurement directly measures with smooth wall reflection, mainly because the distance is relatively close and the signal intensity reflected by light is large enough. From this, we can know that it must be vertical, otherwise the return signal will be too weak to get the distance.
5. Ultrasonic ranging accuracy is relatively low, and it is rarely used.
