Analysis and comparison of radar, differential pressure, and magnetostrictive level gauge

1. Comparison of characteristics

(1) Characteristics of radar level gauge:

(1) The liquid level measurement is not interfered with by temperature changes and medium changes.

(2) If the liquid level range is below 15m, the accuracy error of the measurement is within the range of 5mm, and if the liquid level range is above 15m, the accuracy measurement value is 5mm±0.05%.

(3) There are blind spots at the top and bottom.

(2) Characteristics of differential pressure level gauge:

(1) In many occasions where a traditional differential pressure level gauge is installed, there is additional vapor pressure above the liquid. Since vapor pressure is not part of the level measurement, its presence must be counteracted by capillaries and sealed elements.

(2) Mechanical parts rely on digital structures for substitution, which belongs to a kind of electronic element transmission technology, with faster response speed and higher measurement accuracy.

(3) In the case of severe cold weather, thermal insulation measures or heat tracing measures must be taken to intervene, and the leakage and condensation conditions in the pressure pipeline, whether there is evaporation and blockage are strictly checked.

(4) If the spacing between capillaries is too large, it will have an adverse impact on pressure transmission and increase the error, so the installation process must be improved.

(3) Magnetostrictive level gauge features:

(1) Strong reliability, because the application principle of magnetostrictive level gauge is waveguide, the stainless steel tube is encapsulated in the converter, which does not contact the measuring medium, does not install mechanical moving parts, and does not produce friction and wear, and the sensor works reliably and has a long service life.

(2) High precision. The doctoral guide pulse work belongs to the method of magnetostrictive level gauge application, which will measure the starting pulse and determine the end pulse time to determine the displacement to be measured, with high measurement accuracy, and its resolution is above 0.01% FS, which is unmatched by other sensors.

(3) High security. The tank lid cannot be displayed by magnetostrictive level gauge, which reduces the existence of unsafe factors due to manual measurement, has high explosion-proof performance, and is safe to apply, which can be applied in the measurement of still liquids and chemical raw materials.

(4) The magnetostrictive level gauge adopts high-precision sensor element to facilitate system automation. By calculating the time difference between the pulse current and the torsional pulse by the processor, the float position can be accurately determined. It fully considers a variety of signal connection methods, relies on standard output signals, connects them with communication interfaces, optimizes signal processing methods, effectively networks, promotes the improvement of the level of automation of the measurement system, and improves the degree of transformation.

A comparison of the characteristics of the three types of level gauge equipment is shown in Table 1.

Level gauge

2. Compare working conditions interference

In actual work, the interference and impact of working conditions are shown in Table 2. This can be seen from comparative analysis.

(1) Radar level gauge is suitable for good working conditions, high temperature and environmental requirements, high space requirements for installation occasions, installation must avoid the inlet, reduce false reflection, can not be installed in the middle of the arch tank, can not be installed in the tank wall position, it is best to install in the position of half the radius of the container.

(2) Differential pressure level gauge is suitable for limited working conditions, the sensor produces serious zero point drift, which produces a large measurement deviation, has poor stability and accuracy, is highly susceptible to environmental influence, maintenance is larger, daily maintenance and operation will be affected, maintenance and installation is more difficult, daily maintenance and operation, the workload is very large.

(3) Magnetostrictive level gauge can be applied in all working conditions, with high stability and accuracy, with a small amount of installation and maintenance, no need for maintenance.