【2025 Level Gauges】Technical Differences and Selection of Frequencies for 6GHz/26GHz/80GHz Radar Level Gauges
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This post was last edited by The one on 2025-11-7 07:22
This post was last edited by The one on 2025-11-7 09:11. Case 1: Reactor with a heating coil – Challenge: The coil causes false echoes. Solution: 80GHz radar + intelligent echo mapping technology (capable of identifying >20 interferents)
This post was last edited by The one on 2025-11-7 09:11. Case 2: Low-temperature LNG storage tanks. Challenge: Measurement drift caused by BOG evaporation. Solution: 26GHz radar + nitrogen purging system (purging flow rate ≥ 20 L/min)
This post was last edited by The one on 2025-11-7 09:11. Case 3: Misuse of 80GHz radar for a styrene storage tank (ε=2.1). Challenge: Signal attenuation due to vapor layers. Solution: Switching to 26GHz reduced the fluctuation rate by 70%
Radar level gauges are classified by working principle into FMCW frequency-modulated continuous wave and pulse wave types； Based on their design, antennas can be classified into planar antennas, parabolic antennas, horn antennas, and rod antennas. The appearance and product names of antennas from different manufacturers may vary slightly, but their basic functions remain the same.
The selection of the antenna type for radar level gauges requires comprehensive consideration of specific operating conditions, measurement requirements, and the properties of the medium, in order to ensure measurement accuracy and the long-term stability of the equipment. Medium properties: such as corrosivity, viscosity, volatility, condensation characteristics, etc. Measurement accuracy and range: Select the appropriate antenna type based on the tank capacity and liquid level measurement requirements. Installation environment: such as whether a waveguide is required, the shape of the storage tank (vault tank, floating roof tank), space constraints, etc. Operating conditions: such as temperature, pressure, steam entrainment, etc.
Below are the applicable scenarios and characteristics of different antenna types: 1. Horn antenna. Characteristics: The horn antenna is a common type of antenna used in radar level gauges; it boasts good focusing capabilities and resistance to interference. It is suitable for use in high-temperature and high-pressure environments, but not for corrosive media. Applicable scenarios: Suitable for dome tanks or dome tanks without waveguides. Suitable for large-volume storage tanks, especially when the material level is deep; the measurement distance can reach 70 meters. Not suitable for corrosive media or liquids that easily condense.
2. Parabolic antenna: Features: The parabolic antenna uses point-source radiation, offering strong penetration and focusing capabilities. It is suitable for high-temperature and high-pressure environments, and can effectively prevent condensation and deposition. Applicable scenarios: Suitable for large storage tanks, such as for measuring the level of high-temperature fluids like heated crude oil or residue; the measurement range can reach over 35 meters. Not affected by steam, suitable for applications where steam carries liquids. It can be used in floating roof tanks or internal floating roof tanks, but it needs to be installed in a waveguide to improve accuracy.