Thread Content
This post was last edited by zhoudingshengs on 2023-11-3 at 11:59. Generally speaking, the selection of radar level gauges depends on the following factors: 1. The dielectric constant of the medium being measured directly affects the quality of radar wave transmission. The greater the dielectric constant of the medium, the more pronounced the reflection effect, which is more favorable for measurement. Radar level gauges are not recommended for media with a dielectric constant below 1.4; for media with low dielectric constants, guided-wave radar level gauges are advised. Since the dielectric constant of EO, ethylene oxide, is 14 at room temperature, which is relatively low, it is recommended to use a guided-wave radar level gauge or to incorporate guided waves within the equipment. 2. For measuring the level of crude oil, refined oil, asphalt, ethylene, propylene, liquefied petroleum gas, liquefied natural gas, and other liquids stored in large dome tanks and spherical tanks, it is recommended to use antenna-type radar level gauges ； For level measurement in internal floating roof tanks, external floating roof tanks, tanks under pressure, and tanks equipped with agitators or involving swirl processes, it is recommended to use guided wave radar level gauges. 3. Based on measurement accuracy, radar level gauges can be divided into control grade and metering grade; the accuracy of the control grade should not be lower than ±0.5%, while that of the metering grade should not be lower than ±3 mm. 4. It is recommended that radar level gauges installed on the storage tanks in the tank farm be equipped with auxiliary indicator panels nearby, to facilitate monitoring. 5. The power supply types for radar level gauges are two-wire and four-wire; the two-wire system is generally used at the control level, while the four-wire system can be employed for high-precision measurement applications. Under normal circumstances, a 24V DC power supply is the preferred choice for radar level gauges; if the distance between the installation location and the instrument cabinet is large, a 220V AC power supply should be used. 6. For antenna-type radar level gauges, the appropriate type of antenna should be selected based on the actual operating conditions. The most commonly used type is the flared antenna. Such antennas have good wave-gathering properties, but they are not suitable for measuring corrosive media. Moreover, if the pressure inside the container is too high, leaks can occur, so careful selection is necessary ； For high-pressure equipment or corrosive media, planar-sealed antennas are recommended ； Rod antennas have small installation dimensions, making them suitable for situations where installation conditions are limited. There are various materials available for these antennas, allowing their use in environments with corrosive substances ； Parabolic antennas are not affected by heated steam, and are suitable for large containers with heated steam, such as residue tanks and asphalt tanks.