The accuracy of radar level gauges varies slightly in practical applications from theoretical environments, mainly due to the fact that the interference of microwaves by tanks and their internal obstructions determines the accuracy that can be obtained.
The main factors are:
1. Impedance jump inside the instrument and at the antenna connection;
2. Interference reflection from obstacles inside the tank;
3. Multiple reflections caused by the tank wall, tank top, and tank bottom;
4. Reflection interference caused by ripples on the liquid level surface.
In addition, the characteristics of the liquid level medium have a certain influence on the measurement range. Liquids with a smaller dielectric constant have a greater impact on the measurement distance of the radar level meter, which reduces the measurement range; liquids with a larger dielectric constant have a smaller impact on the measurement distance of the radar level meter, which increases the measurement range. With the continuous development of the petrochemical industry, radar level meters are also constantly improving. In order to adapt to the special requirements of various use environments, various types of radar level meters have implemented serial designs. According to different measurement accuracy requirements, industrial control-grade radar level meters or trade measurement-grade radar level meters can be selected.
The application scope of radar level meter includes the following occasions:
1. Radar level gauges can be used to measure the liquid level of flammable, explosive, highly corrosive media, and are particularly suitable for measuring large vertical tanks and spherical tanks.
2. Radar level gauges are suitable for pressures from vacuum to several MPa, process temperatures from sub-zero to 200°C and up to 400°C when using high-temperature antennas.
3. The accuracy of the instrument is divided into industrial measurement grade and metrology grade accuracy, which can meet different measurement and metrology requirements.
4. Use different installation methods to meet the measurement requirements of spherical tanks, dome tanks, internal floating roof tanks and external floating roof tanks.
The performance of various types of radar level meters has its own characteristics. The appropriate model should be analyzed and determined based on the specific working conditions such as the use requirements, the temperature, pressure, corrosion characteristics of the measured medium, and the size of the space used. For example, different antennas can meet various measurement requirements. The more commonly used cone antenna can be installed on the tank top or waveguide of the buffer tank and storage tank, which is suitable for measurement sites with a large measurement range. The parabolic antenna is suitable for the measurement of liquid and solid material levels and can be used for extremely long distance measurements. The small horn antenna is suitable for small containers, and the flat antenna is suitable for a variety of working conditions. In addition, since the radar level meter uses the method of measuring the empty height to obtain the liquid level, that is, measuring the distance from the tank top measurement reference point to the liquid surface.
Hangzhou Economic Development Area，Hangzhou 310018，China
