Thread Content
There are three frequency bands for the microwaves used in radar level gauges: the C-band (5.8–6.3 GHz), the X-band (9–10.5 GHz), and the K-band (24–26 GHz). In level measurement, microwaves are generally emitted in a directed manner, and the directionality of microwave emission and reception is usually quantitatively expressed by the beam angle. The beam angle is related to the type of antenna as well as the microwave frequency (wavelength) used. For commonly used conical horn antennas, the higher the microwave frequency, the better the beam focusing performance – that is, the smaller the beam angle. This is very important in practical applications. Low-frequency microwave level gauges have wider beams; if not installed properly, they will receive numerous false echoes generated by the internal structure. Moreover, the higher the microwave frequency, the smaller the size of the horn can be, making it easier to install it through openings. There are no microwave (radar) level gauges with frequencies higher than the K-band (24-26 GHz). Due to the lack of distinct application advantages, X-band radar tends to be phased out in the development of level measurement technologies by various level measurement manufacturers. What troubles users in the field of level measurement today is the measurement of levels in large solid silos, especially those that are filled with dust and subject to turbulence at depths of up to 50/100 meters. For example, capacitive or guided-wave radar TDR systems are subject to high tension loads when the liquid level drops during discharge, which may damage the instruments or cause the roof of the tank to collapse. Hammers often suffer from the problem of embedded hammers, requiring frequent repairs; most other mechanical instruments are the same. High-dust environments, on the other hand, may exceed the capabilities of non-contact ultrasonic level measurement systems. High-frequency FMCW radar technology is particularly suitable for level measurement in such large solid material silos! Today’s high-frequency radars are generally radar level gauges operating in the K-band (24–26 GHz). The higher the operating frequency of the radar, the shorter the wavelength of its electromagnetic waves. This enables better reflection from inclined solid surfaces. Additionally, a higher frequency results in a narrower beam width, which helps to effectively avoid obstacles. Moreover, high frequencies allow the use of smaller antennas in radar systems. In a FMCW frequency-modulated continuous-wave microwave level gauge, the transmission and reception of signals occur simultaneously; more microwave signals are transmitted within the same time frame, which helps to reduce signal loss in the measurement of solid materials with high dust levels. Therefore, high-frequency FM radar can provide accurate and reliable measurements in solid material testing; it is also well-suited for use with materials such as PP powder and PE powder in the chemical industry. However, due to technical limitations, there are currently no high-frequency radar level gauges that operate in the K-band and above. Low-frequency radars operating in the 5.8 GHz to 10 GHz range are also used for measuring solids. However, due to their low frequencies and long wavelengths, the emitted waves are not easily diffusely reflected. In environments with high dust concentrations, this results in numerous secondary or multiple echoes, leading to significant interference and noise. Consequently, such radars are gradually being phased out in the measurement of solid powders. Xi’an Dinghua Electronics Co., Ltd., established in 1992 and currently located in Xi’an, Shaanxi Province, is a high-tech enterprise that specializes in the research and development, production, sales, and engineering services of radar level gauges. At present, the company offers a range of products including radar level gauges, external liquid level meters, fork-type level switches, electro-hydraulic actuators, ultrasonic flowmeters, and external thermometers. All of these products have withstood numerous complex operating conditions in actual fields, and are widely used in industries such as petroleum, chemicals, power generation, coal, metallurgy, as well as food and pharmaceuticals. Professional selection guidance, excellent product quality, reasonable prices, fast delivery times, and comprehensive pre-sales, in-sales, and after-sales services…