Radar level meter as a modern industrial process control in the important measurement instrument, its selection is directly related to the stability of the production process and the reliability of the measurement data. In the industrial production environment, the media characteristics of complex and changing, harsh working conditions, how to choose a suitable radar level meter has become a must-have skills for each engineer. This article will start from the practical application point of view, in-depth discussion of radar level meter selection points.

The characteristics of the measurement medium is the primary consideration for selection. The dielectric constant of the medium directly affects the reflection strength of the radar wave, for the medium with low dielectric constant (e.g. liquefied gas, light oils), it is necessary to select a high-frequency radar level meter for water in order to ensure sufficient signal reflection. The measurement range then determines the type and size of the antenna. Large tanks usually need to be equipped with parabolic or array antennas, while smaller vessels can choose horn or rod antennas. The choice of process connection takes into account the structure of the vessel and the installation conditions. Flange connection is the most common way, but in some special occasions, such as the food industry or the pharmaceutical industry, a sanitary connection or a threaded connection may be required. Process temperature directly affects the performance of electronic components, and high temperature conditions require the selection of models with heat sinks or remote mounting. Pressure conditions are related to the sealing performance and structural strength of the instrument, and high-pressure vessels must be selected for the corresponding pressure level.

Frequency selection is the key to radar level meter performance. Low-frequency radar (6.3GHz) has strong penetrating power and is suitable for dusty working conditions, but the measurement accuracy is relatively low. High-frequency radar and FM radar (26GHz/80GHz) have better focusing ability and measurement accuracy, which are suitable for complex working conditions and precise measurement requirements. The choice of antenna type needs to consider the measurement range, media characteristics and installation conditions, horn antenna is suitable for most working conditions, parabolic antenna is suitable for long-distance measurement, and rod antenna is suitable for small container or waveguide tube measurement. Signal processing technology directly affects the reliability of measurement results. Advanced echo processing algorithms can effectively identify the real level echo and eliminate interference signals. In complex working conditions, such as stirring, heating or the presence of internal components, you need to choose a powerful signal processing capabilities of the instrument. Explosion-proof certification is a necessary condition for the selection of hazardous areas, and the corresponding explosion-proof products must be selected according to the regional division. High-temperature and high-pressure conditions pose a serious challenge to custom radar level meter for water. In this case, it is necessary to select a specially designed high temperature resistant model, usually remotely mounted, to isolate the electronic components from the high temperature environment. For containers with agitation, it is necessary to consider the interference of the agitator on the radar wave, choose the model with anti-interference ability, and if necessary, install wave guide tube. Corrosive media require excellent corrosion resistance of the instrument material. The liquid-connected part usually adopts special materials such as Hastelloy and titanium alloy, and the sealing material needs to choose corrosion-resistant fluoroelastomer or PTFE. under vacuum or low-pressure working conditions, attention needs to be paid to the design of antenna, so as to avoid the measurement error due to the pressure change.

The correct selection of radar level meter is a systematic project, need to consider the measurement medium, working conditions, technical parameters and other factors. In the actual selection process, it is recommended to fully communicate with professional and technical personnel, if necessary, on-site testing. With the progress of technology, radar level meter is moving towards higher frequency, stronger signal processing capability, more intelligent direction, which provides more possibilities for industrial measurement. Choosing the right radar level meter not only ensures the measurement accuracy, but also provides reliable data support for the production process control, and ultimately realizes the improvement of production efficiency and product quality.