【Y2025】Differences between 26G and 80G radar level gauges
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The attachment 2.jpg shows the differences between 26G and 80G radar level gauges.
The following response is for reference only: The measurement principle of a radar level gauge is to determine the clear distance in the surrounding space by utilizing the linear propagation property of electromagnetic waves, that is, the straight-line distance between the object being measured and the radar. In industrial applications, this refers to the height between the liquid surface and the radar antenna. By configuring the radar level gauge, it is possible to set the vertical distance from the radar antenna to the bottom of the container; the liquid level height can then be calculated based on the measured height of the liquid surface above that bottom.
Radar level gauges produced by different manufacturers come in various forms, but their basic components are generally the same. These mainly include a circuit section (radar wave generator, signal detection, signal processing), an antenna and receiver, as well as mounting accessories. Depending on the antenna, radar level gauges can be divided into two main types: guided-wave radar and conventional radar.
The antenna of a conventional radar level gauge is merely a device for transmitting and receiving electromagnetic waves. After being emitted, these electromagnetic waves propagate freely through the gas phase. Since the electromagnetic waves used in radar level gauges are high-frequency microwave signals with poor diffusivity, and the distance between the liquid to be measured and the radar level gauge is small, the propagation of these electromagnetic waves can be considered as vertical propagation. Therefore, this type of radar level gauge meets the requirements for measuring liquid levels. Compared to guided-wave radar, it eliminates the need for a guide wave element, resulting in cost savings and easier installation; it is widely used in measuring high liquid levels in storage tanks and similar applications.
Different models of radar level gauges have been developed by various antenna manufacturers to suit different operating conditions. The antennas of conventional radar level gauges used in factories come in four types: flared type, droplet shape (to prevent liquid evaporation and condensation), eccentric type (to avoid interference from multiple reflections of electromagnetic waves), and wide-flared type (to prevent gas-phase media from attenuating electromagnetic waves).
Due to the complexity of the objects being measured, as well as severe damage caused by high temperatures, high pressures, strong corrosion, foam, mixing, steam, and other factors, radar level gauges frequently malfunction. This requires extensive maintenance, which significantly impacts the production facilities. Therefore, it is very necessary to understand the common faults of radar level gauges and their solutions.
Conventional radar uses non-contact measurement, while guided wave radar employs contact measurement; this means that guided wave radar requires more consideration to be given to the corrosiveness and adhesiveness of the medium, and its installation and maintenance become more difficult when it is too long.
Conventional radars can be used interchangeably, whereas guided wave radars generally cannot be interchanged because the length of the guided wave rod (cable) is fixed according to the original operating conditions; as a result, selecting a guided wave radar is more complicated than selecting a conventional radar.
When measuring solid materials, guided wave radar also needs to take into account the stress on the guided wave rod (cable). Due to this stress, the measurement range of guided wave radar is generally not very large, whereas conventional radar is commonly used for tanks with a length of 30 or 40 meters, and can even be used to measure tanks up to 60 meters in length.
In some specific operating conditions, guided wave radar has clear advantages; for example, when there is stirring inside a tank or the medium experiences significant fluctuations, the measurement values obtained using a guided wave radar fixed at the bottom are more stable than those from a movable radar.