The radar level gauge is a non-contact level measuring instrument, which can be applied to measure corrosive liquids and slurries, such as: liquid storage tanks, sewage storage tanks, acid-base storage tanks, and slurry storage tanks. Continuous and accurate measurement during the process, the liquid level gauge is not affected by temperature, pressure, gas, and has no contact with the surface of the medium. It can quickly and accurately measure the level of different media with low maintenance, high performance, high precision, and high reliability. Long service life and other advantages.
The principle of radar level gauge: transmit → reflect → receive, no dielectric constant is required. Sensitivity can be adjusted as required to detect the desired echo from various echoes and complete the measurement.
3 advantages of radar level gauge:
1. Safe and energy-saving, the radar level gauge can not only measure under high temperature and high pressure, but also is extremely accurate, safe and energy-saving. The transmitting power of the radar level gauge is only a few microwatts per square centimeter, so it can be used without any restrictions. It is used in various occasions. In practical applications, the radar signal can be completely shielded by the metal outer wall. The materials used in radar level gauges are chemically and mechanically stable and can be recycled.
2. No maintenance and high reliability, radar waves are not disturbed. Since the components of the radar sensor cannot be disassembled and there is no mechanical wear, the radar level gauge can be used in various occasions. Through the use of advanced materials, radar level gauges are durable to extremely complex chemical and physical conditions, and it can provide accurate, reliable and long-term stable analog or digital level signals.
3. Almost all media can be measured. Whether the radar level gauge signal can be reflected depends on two factors: the conductivity of the measured medium and the dielectric constant of the measured medium. All conductive media can reflect radar signals well. Radar sensors can measure all media with a dielectric constant greater than 1 and 5 (the dielectric constant of air is 1). Although the conductivity of the medium is not very good, it can be very Measure accurately. Radar level gauge is an advanced radar level measuring instrument with a measuring distance of up to 70 meters. The antenna is further optimized, and the new fast microprocessor can perform higher-speed signal analysis and processing, so that the instrument can be used for various strong corrosive liquids.
The antenna of the radar emits narrow microwave pulses, which are transmitted through the antenna. The microwave will be reflected when it touches the surface of the measured medium. The antenna of the radar receives the microwave signal and transmits it to the electronic circuit part. The electronic circuit part automatically analyzes the signal. Converted into a level signal, this process is almost instantaneous due to the extremely fast propagation speed of electromagnetic waves.
When the liquid level of the radar level gauge enters the blind area, the liquid level orientation corresponding to the secondary echo is usually displayed. If the blind area is 0.3m, and the distance from the liquid level to the surface of the transducer (or probe) is 0.2m, the liquid level gauge will display a liquid level value corresponding to a spatial distance of 0.4m. Because the liquid surface reflection is excellent when measuring the liquid level, the sound pulse emitted by the radar liquid level gauge, after being reflected by the liquid surface, will be re-reflected back to the liquid surface after the echo reaches the surface of the transducer (or probe). It is reflected back to the transducer again and accepted, and the echo at this time is the secondary echo. If the reflection conditions are good, multiple echoes (return echoes) may also be received.
Applicable to process vessels with agitation, liquids that are prone to vapor generation, high temperature, low dielectric constant substances. It is not sensitive to the installation position and obstacles in the tank, and has great anti-interference ability to the interference of the installation pipe. Small blind area, the small blind area is only 50mm away from the end of the speaker, using HART or PROFIBUSPA communication. On-site intelligent signal processing improves measurement stability, and automatic false echo suppression eliminates fixed interfering objects.
Blind zone analysis of radar level gauge:
1. There will be some blind spots at the bottom of the measured object: this blind spot refers to a distance where certain accurate data cannot be measured nearby when the antenna is at the bottom. Only after leaving this distance can the data in subsequent measurements be guaranteed to be accurate.
2. There will be a certain blind spot on the top of the object to be measured: during the measurement process, the short distance between the high material surface of the material and the reference point used in the measurement, it is necessary to select an optimal position to measure in order to allow the measurement higher accuracy.
3. There must be a certain distance between the blind area at the top of the radar level gauge and the blind area at the bottom, and this distance is the distance that is really suitable for measurement, but you must find this distance before you can measure it, so that you can measure results are more accurate.
For example, if there is foam on the liquid surface, the foam surface will be identified as the liquid surface; some liquid surface layers will precipitate some other media (such as clear water on the surface of the mud), because it is very thin, the liquid level gauge will use the underlying medium surface as the liquid surface. In some media, the level gauge will use the tank bottom echo as the liquid level signal. In addition: for guided wave radars with dual rods or coaxial probes, the liquid level gauge needs to distinguish whether the interaction between the two electrodes occurs above the liquid level or in the medium. In these cases, adding a dielectric constant can greatly reduce the computational complexity and is sometimes necessary.
The user selects the level gauge reasonably according to the measurement site environment and the medium. Depending on the type, use and structure of the radar level gauge, some radar level gauges require dielectric constant, while others require sensitivity. Then it is necessary to pass, eliminate the unnecessary echoes, and detect the required echoes, and the calculation amount of the liquid level gauge needs to be increased.
The radar level gauge has unparalleled advantages, and the transmission of microwave signals is not affected by the atmosphere, so it can meet the requirements of harsh environments such as volatile gases, high temperature, high pressure, steam, vacuum and high dust in the process. This product is suitable for harsh environments such as high temperature, high pressure, vacuum, steam, high dust and volatile gases. Continuous measurement of different material levels is possible. And it is easy to install and debug, and can be used alone or in a network. The radar level gauge can be widely used in metallurgy, building materials, energy, petrochemical, water conservancy, grain and other industries.
Post time: 18-01-22