利用了电磁波地特殊性能来进行料位检测，电磁波的物理特性与可见光相似，传播速度可以相当于光的速度。 Radar waves are a special form of electromagnetic waves. Radar level gauges use the special properties of electromagnetic waves to detect material levels. The physical characteristics of electromagnetic waves are similar to visible light, and the propagation speed can be equivalent to the speed of light. Its frequency is 300MHz-3000GHz. Electromagnetic waves can penetrate interference sources such as space vapor and dust. They are also easy to be reflected when encountering obstacles. The better the conductivity of the measured medium or the larger the dielectric constant, the better the reflection effect of the echo signal.
The higher the frequency of the radar wave, the smaller the emitted angle, the greater the energy (magnetic flux or field strength) per unit area, and the smaller the attenuation of the wave, the better the measurement effect of the radar level gauge. The first is the principle and technical performance of the radar level gauge, which consists of a radar level gauge: it is mainly composed of transmitting and receiving devices, signal processors, antennas, operating panels, displays, and fault alarms. Transmission to reflection and then reception are the basic working principles of radar level gauges. The radar sensor ground antenna transmits a minimum 5.8GHz radar signal in the form of a beam. The signal returned by the reflection is still received by the antenna. The running time of the radar pulse signal from transmission to reception is proportional to the distance between the sensor and the surface of the medium and the level. Will cause errors in work and achieve the final measurement results.
Example: h = H–vt / 2
Where h is the material level; H is the slot height; V is the radar wave speed; T is the interval between the radar wave transmitting and receiving;
发射能量很低的极短的微波脉冲通过天线系统发射并接收。 The second is the use of advanced technology radar material radar level gauge to transmit very short microwave pulses with very low energy through the antenna system to transmit and receive. Radar waves travel at the speed of light. The running time can be converted into a level signal by electronic components. A special time extension method ensures stable and accurate measurements in a very short time. Even if the working conditions are more complicated, there are false echoes. The latest micro-processing technology and debugging software can accurately analyze the level echoes. The input antenna receives the reflected microwave pulse and transmits it to the electronic circuit. The microprocessor processes the signal and recognizes the echo generated by the micropulse on the surface of the material. The correct echo signal recognition is completed by intelligent software, and the accuracy can reach millimeter level. The distance D from the surface of the material is proportional to the time travel T of the pulse: D = C × T / 2 where C is the speed of light because the distance E of the empty tank is known, then the level L is: L = ED The output passes the height of the input empty tank E (= zero), full tank height F (= full range) and some application parameters to set, the application parameters will automatically adapt the meter to the measurement environment. Corresponds to 4-20mA output. Application medium: The intelligent radar level gauge is suitable for non-contact continuous measurement of the level of liquids, slurries and particles. It is suitable for occasions with large changes in temperature and pressure; inert gas and volatility. It adopts the measurement method of microwave pulse and can work normally in the range of industrial frequency band. The beam energy is low, and it can be installed in various metal, non-metal containers or pipes without harming human body and the environment. Level gauge for measuring material level: 1. This new technique can be used for echo processing. From the ground measurement principle of radar level gauge, we can know some general knowledge. Radar level gauge is processed by radar wave from the probe to the surface of the medium and then returns to With the time of the probe to measure the material level, there are many interference signals mixed in the reflected signal. The technology of processing real echoes and identifying various false echoes has become a radar level gauge that can accurately measure all The key factor, this is very important and needs to be taken seriously by our operators. 2. The measurement data and processing results are affected by many factors such as liquid level fluctuations and random noise. When detecting, the signal will inevitably be mixed with a lot of noise. In order to improve the detection accuracy, our staff must perform some necessary detection signals Processing to eliminate noise as much as possible, which is convenient for our work. Many experiments have proved that the data smoothing method used can achieve satisfactory measurement results. Using this method to measure can effectively overcome the influence of the agitator in the tank on the measurement results. 3. Relevant structural characteristics of radar level gauge The radar level gauge uses the above-mentioned advanced echo processing and data processing technology, plus many characteristics such as high frequency of radar wave itself and excellent penetration performance, so radar material The level gauge has better performance than the contact level gauge and similar non-contact level gauges. This is the product that users prefer to buy. These include: continuous and accurate measurement under severe weather conditions, very simple operation and easy commissioning, accurate and safe, and related energy savings. Generally, as long as it is used in accordance with operating specifications, it is maintenance-free and reliable It is extremely strong and can also measure all media. What has these functions is the advantages of the radar level gauge, which is also the biggest competitive advantage.
安装要求： 1. 推荐距离(1)墙至安装短管的外壁。 Radar level gauge installation requirements: 1. Recommended distance (1) wall to the outer wall of the installation short pipe. 2. The distance from the tank wall is 1/6 of the tank diameter, and the minimum distance is 200mm. 3. Do not install above the inlet (4). 4. If the distance between the meter and the tank wall cannot be maintained, the medium on the tank wall will stick to cause false echoes. When debugging the meter, the false echo storage should be performed. Note: The measurement range is calculated from the point where the beam touches the tank low, but in special cases, if the tank low is concave or tapered, the measurement cannot be performed when the level is below this point. If the medium has a low dielectric constant, when the tank is at a low liquid level, the tank can be seen low. At this time, in order to ensure the measurement accuracy, it is recommended to set the zero point at a low height of C. It is theoretically possible to measure the position of the antenna tip, but considering the effects of corrosion and adhesion, the final value of the measurement range should be at least 100 mm from the antenna tip. For overflow protection, a safety distance can be defined to be attached to the dead zone. The minimum measurement range is related to the antenna. Depending on the concentration, the foam can both absorb microwaves and reflect them, but it can be measured under certain conditions.