Comparison of Ultrasonic Rangefinders and Laser Rangefinders
The principle of ultrasonic ranging is based on the known propagation speed of ultrasonic waves in air. It measures the time required for sound waves to reflect back after encountering obstacles, and calculates the actual distance from the transmitting point to the obstacle according to the time difference between transmission and reception. The ultrasonic rangefinder is composed of an ultrasonic transmitting circuit, an ultrasonic receiving and amplifying circuit, as well as counting and display circuits.
A laser rangefinder is an instrument for accurately measuring the distance to a target by means of laser. When working, it emits a thin laser beam toward the target. Photoelectric elements receive the laser beam reflected by the target, and a timer measures the time from laser emission to reception to calculate the distance from the observer to the target.
Differences between Ultrasonic Rangefinders and Laser Rangefinders
① In terms of accuracy: the measurement accuracy of ultrasonic rangefinders is at the centimeter level, while that of laser rangefinders is at the millimeter level.
② In terms of measuring range: the measuring range of ultrasonic rangefinders is usually within 80 meters. Handheld laser rangefinders can reach up to 200 meters, and laser rangefinder binoculars can measure distances of hundreds of kilometers or even farther (the measurement accuracy of laser rangefinder binoculars is usually 1 meter or tens of centimeters).
③ Ultrasonic rangefinders are prone to false readings. Since ultrasonic rangefinders transmit sound waves with a fan-shaped emission characteristic, many reflected echoes and interference will occur when there are many obstacles along the sound path, leading to false readings. By contrast, laser rangefinders emit an extremely narrow laser beam that bounces back; there is almost no interference as long as the beam can pass through.
④ The price of ultrasonic rangefinders ranges from tens to hundreds of yuan, while laser rangefinders cost from several hundred yuan to thousands or even tens of thousands of yuan, varying greatly depending on accuracy and measuring range.
