Requirements that must be met when choosing a radar level gauge (reposted)

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Radar waves are a special form of electromagnetic waves, and radar level gauges utilize the unique properties of these waves to measure liquid levels. The physical properties of radar waves are similar to those of visible light, and their propagation speed is equivalent to the speed of light. Its frequency ranges from 300MHz to 3000GHz. Radar waves can penetrate interference sources such as space vapor and dust; they are easily reflected when encountering obstacles. The better the electrical conductivity or dielectric constant of the medium being measured, the better the reflection effect of the echo signal. The higher the frequency of the radar waves, the smaller the transmission angle, the greater the energy (flux or field strength) per unit area, and the less attenuation of the waves – all of which lead to better measurement performance in radar level gauges. 　　 Transmitting, reflecting, and receiving are the basic principles behind the operation of radar level gauges. The antenna of the radar transmitter emits a radar output signal of at least 5.8 GHz in the form of a beam. The reflected output signal is still received by the antenna. The time it takes for the radar pulse output signal to travel from transmission to reception is proportional to the distance from the transmitter to the surface of the medium as well as to the level of the substance. What principle does a radar level gauge operate on? A radar level gauge is based on the time-domain reflection principle (TDR). The electromagnetic pulses emitted by such a gauge travel at the speed of light along a steel cable or probe; when they encounter the surface of the liquid being measured, some of these pulses are reflected, forming echoes that return to the pulse transmitter along the same path. The distance between the transmitter and the surface of the liquid is proportional to the time it takes for the pulses to travel between them, and the level height can be determined through calculations. Conditions that must be met when selecting a radar level gauge: (1) Tank volume: For large tanks (10,000–100,000 m³) and relatively large liquefied gas tanks, level gauges with higher performance can be used, while for smaller tanks, ordinary level gauges are sufficient ； (2) Purpose of the liquid storage tank: High-precision level gauges should be used for trade tanks, while ordinary level gauges are sufficient for intermediate tanks ； (3) Liquid level characteristics: When storing liquids with high viscosity at the surface (such as heavy oil), it is advisable to use level gauges that do not come into contact with or have minimal contact with the liquid surface being measured, such as radar, ultrasonic, and magnetostrictive level gauges; for light oils, ordinary level gauges can be used ； (4) Actual user requirements: If the user demands high measurement accuracy with limited investment, a liquid level gauge with good performance can be used. In general, when renovating or upgrading existing tank areas, the selection of liquid level gauges should take into account the condition of the existing ones, striving for consistency in the choice of models. Article source: http://www.yhck88.com/jszc/530.html