Measuring Principles and Methods of Laser Distance Measuring Instruments
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 refraction coefficient 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 phasorimetry does not measure the phase of the infrared or laser, but rather the phase of the signal modulated on top of the infrared or laser. The construction industry has a handheld 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 needs to be fully reflective prisms with the housing measurement with the rangefinder, directly to the smooth wall reflection measurement, mainly because the distance is relatively close, the light reflected back to the signal strength is large enough. With this can be known, must be vertical, otherwise the return signal is too weak will not be able to get the accurate distance.
3. If the measured object plane for the diffuse reflection is possible?
Usually can be, the actual project will use a thin plastic plate as a reflective surface to solve the serious problem of diffuse reflection.
4. Ultrasonic distance measurement accuracy is relatively low, and is rarely used nowadays.
Measuring principle and method
With the development of science and technology, it seems that most people still do not know that there is a laser rangefinder, do not understand the laser rangefinder. Even some workers are still using a tape measure to measure the distance, using a pen to calculate the area 'volume and so on. Below I introduce the principle and use of laser rangefinders, which allows workers to work and study with high efficiency and precision.
Laser rangefinder is the use of laser on the target distance to accurately determine the instrument. Laser rangefinder in the work of the target to shoot a very thin beam of laser light, by the photoelectric components to receive the target reflected laser beam, the timer to determine the laser beam from the launch to receive the time to calculate the distance from the observer to the target.
If the laser is emitted continuously, the range can be up to about 40 kilometers and can be operated day and night. If the laser is emitted in pulses, the accuracy is generally** low, but a good relative accuracy can be achieved for long-distance measurements.
