The laser speed meter is a device that measures the moving distance of the measured object within a certain time interval through laser emission and calculates the moving speed of the object. It is used for online cutting monitoring of plates and pipes, length and speed measurement of cables or sandpaper, etc. It is also suitable for measuring the speed and length of textiles such as flannel and fur, coatings or viscose surfaces, and foam rubber surfaces.

The laser speed meter uses the principle of laser ranging. Laser ranging (i.e. electromagnetic waves with a speed of 300,000 kilometers per second) is to determine the distance between the measured object and the test point by emitting a laser beam to the measured object, receiving the reflected wave of the laser beam, and recording the time difference. Laser speed measurement is to perform laser ranging on the measured object twice with a specific time interval, obtain the moving distance of the measured object in that period, and thus obtain the moving speed of the measured object.

Features of laser speed meter:

1. Since the laser beam is basically a ray, the estimated speed distance is far from the effective distance of radar speed measurement, and can be measured beyond 1000M;

2. High speed measurement accuracy, error <1 km;

3. In view of the principle of laser speed measurement, the laser beam must be aimed at the plane reflection point perpendicular to the laser beam. Since the measured vehicle is too far away and in a moving state, or the vehicle body is not large, the work intensity of the on-duty police officers is very high and they are easily fatigued. The American Laser Technology Company has produced a laser speed meter with a continuous automatic speed measurement function, which is specifically used to solve this problem. The Dongcheng Brigade of the Dongguan Traffic Police Detachment uses this improved speed meter to capture speeding vehicles, and has achieved significant results.

4. In view of the principle of laser speed measurement, the laser speed meter cannot be used in motion and can only be used in a stationary state; therefore, traffic police generally put the instrument on the patrol car and use it when it is parked.

5. The laser speed meter used by most countries uses a class of safe lasers, which are safe for human eyes.

6. The evidence-collecting capability of laser speedometer is far greater than that of radar speedometer, so it is widely recognized and promoted all over the world, such as the United States, Canada, the United Kingdom, Germany, Australia, Sweden, Switzerland, the Netherlands, Guangdong, China, Taiwan, Hong Kong, Macau, etc.

7. The power consumption of laser speedometer is relatively low, and two No. 5 batteries can be used continuously for 20 hours.

The principle of radar speed measurement is to apply the Doppler effect, that is, the moving object has a frequency shift effect on the received electromagnetic wave. The radar speedometer calculates the movement speed of the measured object based on the calculation of the frequency shift of the received reflected wave. Therefore, it has the following characteristics:

1. The irradiation surface of the radar beam is larger than that of the laser beam (ray), so the radar speed measurement is easy to capture the target without precise aiming.

2. The radar speed measurement equipment can be installed on patrol cars. The detection of vehicle speed in motion is a very important part of the "mobile electronic police", but unfortunately the evidence collection is not strong enough.

3. The fixed speed measurement error of radar is ±1Km/h, and the measurement error during motion is ±2Km/h.

4. The electromagnetic wave beam emitted by the radar has a certain angle, so the effective speed measurement distance is closer than that of the laser speed measurement.

5. The angle of the radar speed meter's emission beam is a very important technical indicator. The larger the angle, the more easily the speed measurement accuracy is affected; conversely, the impact is smaller.

6. If the antenna of the speed radar is not placed properly, when the terrain is not flat, the reading of the target vehicle will be replaced by the speed of other vehicles.

7. If there is an object with stronger reflective ability next to the target, the speed radar can only measure the object with strong reflective ability.

8. When there are two cars running in parallel, the radar speed meter cannot tell which car is the speeding vehicle.

9. When the measurement signal is reflected multiple times, the result measured by the speed radar will also be wrong.

10. Radio waves will interfere with the speed radar, causing the measurement result to be distorted.

11. Radar sensors can detect radar speed meters but it is extremely difficult to detect the existence of laser speed meters.