The Basis and Options for a Laser Range Finder
The laser rangefinder is an instrument that uses laser to accurately measure the distance of the target. When the laser range finder is working, it emits a very thin laser beam to the target, and the photoelectric element receives the laser beam reflected by the target. The timer measures the time from the launch to the reception of the laser beam, and calculates the distance from the observer to the target. The laser range finder is light in weight, small in size, easy to operate, fast and accurate, and its error is only one-fifth to several hundredths of other optical range finders.
Principle:
1. The principle of using infrared ranging or laser ranging
The principle of ranging can basically be attributed to measuring the time required for light to go back and forth to the target, and then calculate the distance D through 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 continuous wave, which is called phase measuring range finder. Of course, there are also pulse range finders, typically 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. The construction industry has a handheld laser distance meter for house surveying that works on the same principle.
2. The plane of the measured object must be perpendicular to the light
Generally, precision distance measurement requires the cooperation of a total reflection prism, while the rangefinder used for house measurement directly measures with smooth wall reflection, mainly because the distance is relatively short and the signal strength of the light reflected back is large 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. The object plane can be measured as diffuse reflection
It is usually possible. In actual engineering, thin plastic plates are used as reflective surfaces to solve the problem of serious diffuse reflection.
4. The accuracy of ultrasonic ranging is relatively low, and it is rarely used.
5. The accuracy of the laser rangefinder can reach 1 mm error, suitable for various high-precision measurement purposes
Purchase:
Points to consider when purchasing a range finder:
1. Measuring range
2. Measurement accuracy
3. Where to use
It is basically divided into the following situations:
a) It only needs to measure the distance within a few meters or a dozen meters,
And when the accuracy requirement is not high.
Laser Range Finder
Laser Range Finder
Suggestion - "ultrasonic rangefinder" can be selected.
Remarks--The measurement effect of the ultrasonic range finder is greatly affected by the environment, and its stability and directionality are worse than that of the laser range finder, but the price is relatively cheap, and it is suitable for indoor measurement.
b) The measurement distance is not long, and it is mostly used indoors, requiring high precision.
Suggestion - Optional "Handheld Laser Rangefinder".
Remarks--The handheld laser rangefinder is suitable for indoor use, and the measurement accuracy and effect are very good.
(If the user needs to detect in an outdoor environment, it is recommended to use a laser sight and a reflector in combination to achieve the expected range and effect.)
c) The measurement distance is relatively long, and it is mostly used for outdoor use.
Suggestion - buy "telescopic laser rangefinder" (ie: laser rangefinder telescope)
