Have you seen a handheld laser rangefinder?

The accuracy of laser rangefinders mainly depends on the calculation accuracy of the time between laser emission and reception by the instrument. According to the technology and applications used, laser rangefinders can be divided into conventional laser rangefinders with an accuracy of about 1 meter ( Mainly used for outdoor sports, hunting, etc.) and high-precision laser rangefinders used in surveying and mapping, land surveying, construction, engineering applications, military and other occasions that require high accuracy.
The phase method rangefinder is a rangefinder that modulates the phase of the laser, and obtains the distance by measuring the phase difference of the reflected laser light. Due to the need to detect the reflected laser phase, the received signal needs to have a strong intensity. Considering the safety of the human eye, the telephoto system like a pulsed laser rangefinder cannot be used, and the range is small The typical range of distance measurement is 0.5mm to 150 meters. The general phase method laser rangefinder uses a 635-nanometer (visual red) laser as the debugging object. It is also commonly known as an infrared rangefinder, but the definition of laser is not The color is defined, and if the 635-nanometer laser rangefinder is directly irradiated to the human eye, it will cause irreversible damage. Please use and protect it correctly.
Because the speed of ultrasonic propagation in the air is greatly affected by temperature, humidity, air pressure, etc., the measurement error is large, and the longer the ultrasonic wave length leads to a shorter propagation distance, so the general ultrasonic rangefinder has a shorter measurement distance , The measurement accuracy is relatively low. However, using the characteristics of fan propagation of ultrasonic waves, its detection range is larger than that of photoelectric rangefinders. It is widely used in safety protection, cable height measurement, obstacle detection and other fields in practical engineering.