Laser rangefinder usually adopts two methods to measure the interval: pulse method and phase method. The pulse rangefinder works like this: the laser emitted by the rangefinder is reflected by the measured object and then accepted by the rangefinder, which also records the time when the laser goes back and forth. Half the product of the speed of light and the time of return is the distance between the rangefinder and the measured object.The accuracy of pulse measurement interval is generally around +/-1 m.Other, this kind of rangefinder measurement blind area is generally about 15 meters.
Laser rangefinders are now widely used in the following fields: electricity, water conservancy, communications, environment, architecture, geology, police, fire, explosion, navigation, railway, counter-terrorism/military, agriculture, forestry, real estate, leisure/outdoor sports, etc.
Literally, the laser rangefinder USES laser as the main operating material to carry on the operation. Currently, handheld laser rangefinders operate in the following types of materials: semiconductor lasers with operating wavelengths of 905 nanometers and 1540 nanometers, and YAG lasers with operating wavelengths of 1064 nanometers. The 1064 nanometer wavelength is harmful to human skin and eyes, especially if the eye accidentally touches the 1064 nanometer wavelength laser, the damage to the eyes may be permanent.So, in foreign countries, handheld laser rangefinders, the 1064 nanometer laser is completely cancelled.In China, some manufacturers also produce laser rangefinders with 1064 nanometers.
We call the 905 nanometers and 1540 nanometers laser rangefinders "safe."With regard to the laser rangefinder with 1064 nanometers, we call it "unsafe" because of its potential harm to human body.