The characteristics and classification of range finder
The laser range finder is an instrument that uses a certain parameter of the modulated laser to accurately measure the distance of the target. The pulsed laser rangefinder emits a beam or a sequence of short-lived pulsed laser beams to the target when it is working, 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 meter to the target.
How Laser Rangefinders Work
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 laser rangefinder 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. Laser plummet can measure the object plane as diffuse reflection
It is usually possible. In actual engineering, a thin plastic plate is used as a reflective surface to solve the problem of serious diffuse reflection.
3. The plane of the measured object must be perpendicular to the light
Usually precision distance measurement requires the cooperation of a total reflection prism, while the rangefinder and infrared thermometer used for house measurement directly measure 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 accurate distance cannot be obtained.
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, which is suitable for various high-precision measurement purposes.
Features of Distance Meter:
Convenience: no need for reflectors, use anytime, anywhere, even in bad weather
Pocket: Small and exquisite, light and easy to carry, user-friendly hand-held patented design
Safety: Adopt CLASS1 transparent laser which is harmless to eyes
Flexible: The measurement unit can be converted between "yard" and "meter" at any time
High precision: the maximum error is not more than 1 meter
Rain mode, rain will not affect the measurement
>150m mode: Can not be affected by nearby sparse trees, long-distance ranging
LCD display sight, the data status is clear at a glance
Quiet operation, automatic power off, standard battery
Built-in tripod standard interface
Measuring range: 10-1500 meters, the minimum measuring distance can be 10 yards,
Highly reflective target: 1500 meters (about 1642 yards)
General building: 1200 meters (about 1314 yards)
big
Type animal: 600 meters (about 657 yards)
Weight: 420g (without battery)
Classification of rangefinders
1. Handheld laser range finder
The measurement distance is generally within 200 meters, and the accuracy is about 2mm. This is the most widely used laser rangefinder at present. Functionally, in addition to measuring the distance, it can also generally calculate the volume of the measured object.
2. Cloud service laser range finder
The measurement data on the laser rangefinder is transmitted to mobile terminals such as mobile phones and tablet computers in real time through Bluetooth; the data can be transmitted to the cloud server through wifi networking, and the measurement data can be shared in real time with remote construction partners.
3. Telescopic laser range finder
The measurement distance is relatively long, and the general measurement range is about 3.5 meters to 2000 meters. There are also ranging telescopes with a maximum range of about 10 kilometers. Due to the collimation requirements of the ranging telescope, the blind area is below 3.5 meters, and the laser is greater than 2000 meters Telescopes generally use YAG lasers with a wavelength of 1.064 microns. In order to achieve a larger measurement range, the laser power is relatively high. Users are advised to pay attention to laser protection. The main application range is outdoor medium and long distance measurement.
