Difference between contact and non-contact radar level gauges

Thread Content

Contact-type radar level gauge: Principle: Microwave pulses are guided downward along a guide rod to the material; part of these signals is reflected back, and the level is determined by measuring the time difference between the signal emission and its reception. Suitable for storage tanks with small capacities, as well as complex tanks with complex geometries and internal obstacles. Suitable for applications with steam, deposits, foaming, and condensation water. Advantages: Guided wave radar has clear advantages in certain special operating conditions. For example, in situations where there is stirring inside a tank or significant fluctuations in the medium, measurements taken using a guided wave radar fixed at the bottom are more stable compared to those from conventional radars. Another scenario is level measurement in small tanks; due to the limited space available for installation or the presence of many interfering elements inside the tank, conventional radars are not suitable, and it is then that the advantages of guided wave radar become evident. Additionally, in conditions with a low dielectric constant, both conventional radars and guided wave radars rely on the differences in the dielectric constant of the medium. Since the waves emitted by conventional radars spread out, the signal becomes too weak and unstable when the dielectric constant is too low. In contrast, the waves from guided wave radars propagate along the guided wave rod, resulting in relatively stable signals. Moreover, most guided wave radars have a bottom detection function that allows for adjustments based on the echo signals from the bottom, thereby enhancing the stability and accuracy of the measurements. Applications: Used in liquid storage tanks, acid and alkali storage tanks, slurry storage tanks, solid particles, and small oil storage tanks. Such as: coal bins, ash bins, oil tanks, acid tanks, etc. Non-contact radar level gauge: Principle: Microwave signals sent into the storage tank are reflected back from the surface of the material; by measuring the time difference or frequency difference between the emission and reception of these signals, the level height of the material can be determined. Suitable for harsh operating conditions such as high corrosion levels and requirements for hygiene and sterility ； Suitable for storage tanks, reaction vessels, and process tanks under various process conditions ； Suitable for measurement applications with high precision requirements. Advantages: Continuous level measurement for liquids, particles, and slurries. The measurement of radar level gauges is not affected by the medium, temperature, inert gases, steam, dust, foam, etc., making them suitable for use in explosive hazardous areas. Application: It does not come into direct contact with the medium, making installation convenient. When measuring the amount of solid material, there is no need to consider the impact of the material on the antenna. It can meet the requirements of complex operating conditions. For example: special environments such as high dust levels, foam, dew formation, crystallization, etc.