Radar level meter can perform non-contact level measurement under any process conditions. It reflects microwave signals from above to the medium, and the surface of the medium reflects it again. Based on the received signal, the level meter can measure the distance between the medium and calculate the accurate level.

Whether the medium you need to measure is liquid, solid, high temperature, low temperature, or corrosive, radar level meter can meet all your applications.

This article will take you to familiarize yourself with the terms you often encounter for powder silo radar level sensor, or fuel level sensor with 0-30m range.

1. Dielectric constant

The dielectric constant refers to the ratio of the capacitance when the same substance is used as the dielectric and vacuum in the same container, which is used to measure the ability of the substance to hold a charge.

The dielectric constant is crucial to measuring the type and properties of the material. Different materials have different dielectric constants due to different molecular structures and compositions. Generally speaking, the higher the dielectric constant, the stronger the response of the material to the electric field, while the lower the dielectric constant, the weaker the response of the material to the electric field.

2. Working frequency

The working frequency of the radar level meter refers to the frequency range of the radar waves it sends. Radar level meters can be divided into high-frequency radar and low-frequency radar according to the transmission frequency of the radar wave. The transmission frequency of low-frequency radar is between 100MHz and 8GHz, and radars above 8GHz are classified as high-frequency radar level meters.

In actual engineering, low-frequency radar level meters are mainly used to measure liquid media and small-range environments, while high-frequency radars have a larger range due to their high energy and other advantages, and can be applied to more working conditions. The radar waves of high-frequency radar level meters are better than low-frequency radars for measuring irregular surface materials such as solid materials, powders and particles.

The working frequency has an important impact on the performance and application of radar level meters, which is specifically manifested as follows:

·Penetration ability: The higher the working frequency, the worse the penetration ability of radar waves. However, high-frequency radar waves will be greatly attenuated when passing through liquids or solid materials. Therefore, in some cases, low-frequency radar level meters may be more suitable for measuring denser materials.

·Measurement accuracy: High-frequency radar waves have shorter wavelengths, so they can provide higher measurement accuracy. In contrast, low-frequency radar waves may be more susceptible to more interference, thus affecting the accuracy of measurement.

3. Blind Zone

The blind zone of a radar level meter refers to an area where radar waves cannot accurately measure, usually near the radar antenna. The blind zone is caused by the physical structure of the radar and the signal propagation characteristics. Specifically, it is impossible to accurately detect the position of the target or measured object within a certain distance. The accuracy of the measurement data can only be guaranteed after leaving this distance.

Blind zones may be caused by many reasons such as geographical conditions, electromagnetic wave propagation characteristics, target speed and the radar itself. Blind zones have a significant impact on the measurement accuracy of radar level meters. Therefore, it is very important to choose products with smaller blind zones when selecting.

The main reasons for the existence of blind zones include:

·Near-field Effect: In the near-field area near the radar antenna, the characteristics of signal propagation are different from those in the far-field area, which may cause signal attenuation or unclear reflection, resulting in blind zones.

·Antenna design: The design and layout of the radar antenna will affect the formation of blind zones. For example, some antenna structures may have a larger radiation beam in a specific direction, resulting in a larger blind area in that direction.

·Beam angle: The beam angle of the radar will also affect the size of the blind area. The smaller the beam angle, the larger the blind area will usually be, because the radar wave is more susceptible to obstacles or interference and cannot reach the target area.

·Environmental interference: The installation and use environment also have a certain impact on the blind area of the radar level meter. For example, metal structures or other obstacles may cause reflections or attenuation on the propagation path of the radar wave, resulting in blind areas in these areas.

4. Echo

The working principle of the radar level meter is that the signal sent by the echo ranging radar level meter is reflected back by the surface of the material to form a signal. The time difference between the transmitted wave and the received wave is proportional to the distance between the material surface and the antenna. The propagation time can be measured to determine the position and height of the material.

5. Beam angle

The beam angle is a key parameter to measure the directivity and scanning range of the radar beam. The beam angle of the radar level meter, also known as the antenna beam width, refers to the main radiation angle range of the electromagnetic beam emitted by the radar antenna, which determines the range and directivity of the radar system in space. When the beam angle is small, the radar’s directivity is more accurate, and the range of receiving or transmitting directions is relatively narrow; conversely, when the beam angle is large, the radar’s directivity is more dispersed, and the range of receiving or transmitting directions is wider.

6. Far and near distances

The far and near distances of the radar level meter refer to the maximum and minimum distance ranges that it can effectively measure.

· Far Distance: refers to the maximum distance that the radar level meter can measure. Generally, the far distance depends on factors such as the power, frequency, antenna design, and environmental conditions of the radar wave. Radar level meters with higher power and frequency can usually cover a longer distance range.

· Near Distance: refers to the minimum distance that the radar level meter can measure. Within the measurement range of the radar level meter, there is usually a close range blind area, in which the radar system cannot accurately measure the distance or height of the object. The close distance depends on factors such as the antenna design, beam angle and signal processing capability of the radar level meter.

The determination of the long and short distances is crucial for the application of radar level meters. When selecting and deploying radar level sensor with local display, it is necessary to determine the appropriate long and short distance ranges based on the actual application requirements and scene characteristics to ensure that the radar system can effectively meet the measurement and monitoring requirements.