Application of laser rangefinder in engineering inspection

Laser rangefinders are generally measured in two ways: pulse method and phase method. The process of pulse method distance measurement is as follows: the laser emitted by the rangefinder is reflected by the measured object and then received by the rangefinder, and the rangefinder records the round-trip time of the laser at the same time. Half of the product of the speed of light and the round-trip time is the distance between the rangefinder and the measured object. The accuracy of the pulse method distance measurement is generally around plus or minus 1 meter. In addition, the measurement blind area of ​​this type of rangefinder is generally around 15 meters.

　　Laser rangefinders have been widely used in many fields: environment, electricity, police, water conservancy, communications, construction, geology, fire fighting, blasting, navigation, railways, anti-terrorism/military, agriculture, forestry, real estate, leisure/outdoor sports, etc.

　　Why is there a difference between "safe" and "unsafe" laser rangefinders?

　　As the name implies, laser rangefinders use laser as the main working material to work. At present, the working materials of handheld laser rangefinders on the market are mainly the following: semiconductor lasers with working wavelengths of 905 nanometers and 1540 nanometers, and YAG lasers with working wavelengths of 1064 nanometers. The wavelength of 1064 nanometers is harmful to human skin and eyes, especially if the eyes accidentally come into contact with the laser of 1064 nanometer wavelength, the damage to the eyes may be permanent. Therefore, in foreign countries, the 1064 nanometer laser is completely banned in handheld laser rangefinders.

　　Here are some things to consider when choosing a rangefinder:

　　***1. Measurement range

　　***2. Measurement accuracy

　　***3. Occasions of use

　　Basically, it can be divided into the following situations:

　　a) Only a few meters or more than ten meters are needed for distance measurement.

　　And the accuracy requirement is not high.

　　*Recommendation - You can choose to use an "ultrasonic rangefinder".

　　*Note: The measurement effect of ultrasonic rangefinder is greatly affected by the environment, and its stability and directionality are worse than those of laser rangefinder, but it is relatively cheap! It is suitable for indoor measurement.

　　b) The measuring distance is not long, it is mostly used indoors and requires high accuracy!

　　*Recommendation - You can purchase a "handheld laser rangefinder".

　　*Recommendation – Swiss LEICA A5 series handheld laser distance meter;

　　Swiss LEICAA3 digital laser rangefinder;

　　*Note: Handheld laser rangefinders are best used indoors, and their measurement accuracy and effects are very good!

　　(If the user needs to detect in an outdoor environment, it is recommended to use a professional laser sight.

　　The calibrator and reflector must be used together to achieve the expected measurement range and effect.

　　c) The measuring distance is far, mostly used outdoors!

　　* Recommendation - Buy a "telescopic laser rangefinder" (ie: laser rangefinder telescope)

　　*Features: It is both a telescope and a rangefinder! With multiple observation magnifications, users can easily aim at the target and measure the distance through the crosshair system inside the eyepiece! It uses transparent infrared laser emission and reception that is harmless to the eyes to accurately measure the target distance. It is small, light and easy to carry!