Principle and application of infrared rangefinder
The principle of using infrared ranging or laser ranging can basically be attributed to measuring the time required for light to travel to and from the target, and then calculate the distance D 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 the continuous wave, which is called a phase-measuring rangefinder. Of course, there are also pulsed rangefinders, typically WILD's DI-3000. It should be noted that phase measurement does not measure the phase of the infrared or laser, but the phase of the signal modulated on the infrared or laser. The construction industry has a handheld laser rangefinder for house measurements that works the same way.
1. The plane of the object to be measured should be perpendicular to the light. Usually, a total reflection prism is required for precise ranging, and the rangefinder used for house measurement is directly reflected on a smooth wall, mainly because the distance is relatively close, and the light reflected back signal Strong 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.
2. It is usually possible to measure the plane of the object as diffuse reflection. In practical projects, a thin plastic plate will be used as the reflective surface to solve the problem of serious diffuse reflection.
3. The accuracy of the laser rangefinder can reach 1 mm error, which is suitable for various high-precision measurement purposes.
