Measuring principle and measuring method of a hand-held laser range finder
1. What is the principle of distance measurement using infrared or laser? The principle of distance measurement basically boils down to measuring the time it takes for light to travel to and from a target, and then calculating the distance D from the speed of light c = 299792458m/s and the atmospheric refractive index n. Since it is difficult to measure the time directly, it is common to measure the phase of a continuous wave, known as a phasor rangefinder. Of course, there are also pulsed rangefinders, typically WILD's DI-3000. It is important to note that phasor measurement is not a measurement of the phase of the infrared or laser, but rather a measurement of the phase of the signal that is modulated on top of the infrared or laser. The construction industry has a hand-held laser rangefinder for house measurements, which works on the same principle.
2. Does the plane of the object to be measured have to be perpendicular to the light? Usually precision ranging requires fully reflective prisms, while the rangefinder used for house measurement directly reflects the measurement with a smooth wall surface, mainly because the distance is relatively close, and the signal strength of the light reflected back is large enough. With this can be known, must be perpendicular, otherwise the return signal is too weak will not be able to get an accurate distance.
3. If the plane of the measured object is diffuse reflection is it possible? Usually can be, the actual project will use a thin Plastic plate as a reflective surface to solve the problem of serious diffuse reflection. 4.
4. ultrasonic distance measurement accuracy is relatively low, now rarely used.
