Introduction to the concept and classification of range finder
A rangefinder is a dead reckoning instrument used to measure distance to a target, shaker/oscillator, for dead reckoning. There are many forms of rangefinders, usually a long cylinder, composed of an objective lens, an eyepiece, and a rangefinder knob, used to measure the target distance.
Ultrasonic distance meter
The ultrasonic range finder measures according to the characteristics of ultrasonic waves reflected back when encountering obstacles. The ultrasonic transmitter emits ultrasonic waves in a certain direction, and starts timing at the same time as the emission. The ultrasonic waves propagate in the air, and return immediately when encountering obstacles on the way, and the ultrasonic receiver immediately interrupts and stops timing when it receives the reflected wave. By continuously detecting the echoes reflected by obstacles after the generated waves are emitted, the time difference T between the emitted ultrasonic waves and the received echoes is measured, and then the distance L is calculated.
Ultrasonic range finder, because the ultrasonic wave is greatly affected by the surrounding environment, so the general measurement distance is relatively short, and the measurement accuracy is relatively low. At present, the scope of use is not very wide, but the price is relatively low, generally around several hundred yuan.
Infrared distance meter
An instrument that uses modulated infrared light for precise distance measurement, and the measurement range is generally 1-5 kilometers. The non-diffusion principle of infrared rays is used: because infrared rays have a small refractive index when passing through other substances, long-distance rangefinders will consider infrared rays, and the propagation of infrared rays takes time. When infrared rays are sent from the rangefinder When encountering a reflective object, it is reflected back and received by the rangefinder, and then the distance can be calculated according to the time from sending out to being received by the infrared ray and the propagation speed of the infrared ray
The advantages of infrared ranging are cheap, easy to manufacture, and safe, but the disadvantages are low accuracy, short distance, and poor directionality.
How to use the laser range finder
1 Touch the start/measure key to turn on the rangefinder.
2. Use the plus or minus key to change the measurement reference edge as required (only valid for a single measurement), A—front edge; B—instrument support; C—back edge.
3 Aim the laser at the target, touch the start/measure button again, and record the measured value.
4 After measuring, press the Clear key until the initial screen appears. Press the plus and minus keys simultaneously to turn off the rangefinder.
5 If there is no work order for 90 seconds, the rangefinder will automatically shut down.
6 The rangefinder can be self-calibrated by using the standard distance, and can be corrected through the Offset menu item.
