The radar level gauge can also be called a microwave level gauge, which emits microwaves to the measured target, and then the echoes reflected by the measured target are returned to the transmitter for reception, and then the echo is compared with the transmitted wave, and then determined The presence of the target and calculates the distance from the launcher to the target. Radar level gauges can be divided into two types: non-contact and contact types. Among them, the fastest-growing level measuring instrument in recent years is non-contact microwave level gauges.
，物位计则安装在料仓顶部，不与被测介质直接接触，而测量的微波在料仓上部空间内传播与返回。 Generally, the horn or rod antenna is used to transmit and receive microwaves. It is a non- contact microwave level meter . The level meter is installed on the top of the silo and does not directly contact the measured medium. The measured microwave propagates in the upper space of the silo And return. Advantages of non-contact microwave level meter: installation is relatively simple, maintenance is small, and it is not affected by gas components, dust, temperature changes in the silo.
Generally, a metal waveguide is used to conduct microwaves. It is a contact-type microwave level meter . The meter is first installed from the top of the silo, and the probe rod reaches the bottom of the silo. The emitted microwave propagates down the outside of the waveguide and is reflected when it reaches the surface of the material. The receiver is received along the waveguide back to the transmitter.
Radar level gauges generally use the measurement method of microwave pulses, which can work normally in the range of industrial frequency bands. The beam energy is very low. It can be installed in various metal, non-metallic containers or pipes without harming human body and the environment. 适用的场合有：对液体，浆料及颗粒料的物位进行非接触式连续测量，同时使用于温度，压力变化大，有惰性气体及挥发存在的场合 。 The radar level gauge is suitable for: non-contact continuous measurement of the level of liquids, slurries and particles, and is also used in situations where the temperature, pressure changes are large, and inert gases and volatilities are present .