采用发射—反射—接收的工作模式。 The radar level meter adopts the working mode of transmitting-reflecting-receiving. The radar level gauge's antenna emits electromagnetic waves. These waves are reflected by the surface of the measured object and then received by the antenna. The time from when the electromagnetic wave is transmitted to when it is received is proportional to the distance to the liquid surface.
Where D-the distance from the radar level gauge to the liquid surface
C——speed of light
T——Electromagnetic wave running time
记录脉冲波经历的时间，而电磁波的传输速度为常数，则可算出液面到雷达天线的距离，从而知道液面的液位。 The radar level meter records the elapsed time of the pulse wave, and the transmission speed of the electromagnetic wave is constant, the distance from the liquid surface to the radar antenna can be calculated, so as to know the liquid level of the liquid surface. In practical applications, there are two methods for radar level gauges, namely FM continuous wave and pulse wave. The liquid level gauge using FM continuous wave technology has large power consumption, and must adopt a four-wire system, and the electronic circuit is complicated. The level gauge using radar pulse wave technology has low power consumption and can be powered by two-wire 24V DC. It is easy to achieve intrinsic safety, high accuracy, and a wider range of applications. The biggest difference is the use of sound waves for ultrasound and electromagnetic waves for radar. And the penetration and directivity of ultrasonic waves are much stronger than electromagnetic waves, which is why ultrasonic detection is now more popular. Differences in main applications: 1. Radar measurement range is much larger than ultrasonic. 2. Radar has horn type, rod type and cable type. Relative ultrasonic waves can be applied to more complicated working conditions. 3. Ultrasonic accuracy is not as good as radar. 4. The relative price of radar is high. 5. When using radar, consider the dielectric constant of the medium. 6. Ultrasound cannot be used in vacuum, high steam content or foam on the liquid surface.
计测量装置前景广阔，我国这些年工业发展迅速，种类逐渐齐全，而物位测量仪表作为工业生产不可缺少的重要仪表，需求量很大。 Radar level meter measuring devices have a bright future. In recent years, China's industry has developed rapidly, and the types have gradually become more complete. Level measuring instruments, as an indispensable important instrument for industrial production, have a large demand. The attractiveness of the huge market has also created fierce competition. Although there are many domestic manufacturers of level meters, most of them are products with low technical content and low accuracy. Even if the sales volume is considerable, the economic benefits are not considerable. What kind of products can effectively occupy the domestic level instrument market, the key lies in the development and production of advanced and accurate high-end products.
According to surveys by relevant agencies, among the purchase standards for level measurement devices, the most concerned factors are: accuracy, reliability, durability, ease of operation, price, and technical support. Obviously, accuracy is the primary parameter that people care about. And many market forecasts have confirmed this view. According to the research report of ARC Consulting Group, the radar level gauge measurement device will be the most promising measurement device in the field of continuous level measurement. As effective cost control and increased efficiency become more and more important to users, high-precision measurement devices are becoming more and more popular. With the decline in prices and the increasing recognition of their technology, the use of radar measuring devices in industry has become more and more widespread, not just in fuel tanks. Therefore, the radar level gauge measuring device has occupied an increasing market share with its continuous technological innovation. ARC estimates that the global radar level instrument market will reach US $ 388 million by 2007, with an annual growth rate of 10.3%. When radar-type level instruments have achieved this considerable growth rate, other level measurement technologies are struggling for single-digit annual growth rates. Unlike many traditional level measurement processes, radar measurement devices have very high accuracy and can adapt to a variety of very harsh measurement environments. Measurements do not rely on environmental factors such as process density, pressure, and temperature. Manufacturers use these advantages to give Users provide better and better products. As radar-based level technology enters the mature stage of its life cycle, its widespread adoption is largely driven by its fast ROI (return on investment), low maintenance, and high reliability features. Users believe that radar-based level meters can provide high cost performance and can be implemented smoothly even with increasing numbers. As a level measurement technology for the first time for tank reserve measurement, it indicates that the radar level gauge device has made significant progress in the broader process level measurement field.
In ARC's research report, contact and non-contact level measurement devices are generally divided into three categories: high-end products, mid-end products and low-end products. In general, radar measurement devices will have a good market prospect, but they will still be "challenged" by traditional measurement devices. Suppliers are best to make their own market strategies based on their market share and the growth rate of the entire market . Looppowered devices, which are currently favored by the process control industry, are now very common. In addition, battery-powered and wireless radar-type level instruments have also begun to appear on the market. The continuous advancement of various related technologies and the effective control of the cost of radar level gauges are effectively promoting the continuous growth of the radar level gauge market. Using radar-type level instruments to replace traditional level measurement technology will bring huge business opportunities for radar suppliers.