The principle and purchase of laser rangefinder
A laser rangefinder is an instrument that uses laser light to accurately measure the distance to a target. When the laser rangefinder is working, it emits a very thin laser beam towards the target. 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. 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 that of other optical rangefinders.
principle:
1. The principle of using infrared ranging or laser ranging
The principle of ranging can basically be summarized as measuring the time it takes for light to return to the target, and then calculating the distance D through the speed of light c =299792458m/s and the atmospheric refractive index n. Since it is difficult to directly measure time, the phase of a continuous wave is usually measured, which is called a phase-measuring distance meter. Of course, there are also pulse rangefinders, the typical one is WILD's DI-3000.
It should be noted that phase measurement does not measure the phase of infrared or laser, but the phase of the signal modulated on infrared or laser. There is a handheld laser rangefinder used in the construction industry for house surveying that works on the same principle.
2. The plane of the measuring object must be perpendicular to the light
Usually precise distance measurement requires the cooperation of a total reflection prism, but the rangefinder used for house measurement directly measures the reflection of a smooth wall, mainly because the distance is relatively close and the signal strength of the light reflection is strong enough. It can be known from this that it must be vertical, otherwise the return signal is too weak and the distance cannot be obtained.
3. Can measure the diffuse reflection of the object plane
This is usually possible. In actual projects, thin plastic plates are used as reflective surfaces to solve the problem of serious diffuse reflection.
4. Ultrasonic ranging has relatively low accuracy and is rarely used.
5. The accuracy of the laser rangefinder can reach 1 mm error, which is suitable for various high-precision measurement purposes.
Shop:
1.Measurement range
2.Measurement accuracy
3.Use occasions
