Thread Content
This post was last edited by Xidian Hua Electronics on 2023-2-22 at 11:06. There are two types of radar level gauges that are widely used in the market today: pulse-type radar level gauges and guided-wave radar level gauges. Today, let’s briefly compare these two different types of radar. Pulse radar emits narrow microwave pulses, which are transmitted downward via an antenna. After encountering the surface of the medium being measured, microwaves are reflected back and captured by the antenna system, which then transmits the signal to the electronic circuitry, where it is automatically converted into a level signal. Advantages: 1. It can measure up to 70 meters with an error of 3 millimeters, and it is not affected by factors such as temperature, dust, or steam. 2. It has a wide range of applications and can be used for continuous measurement in various types of storage tanks, LPG tanks, reaction vessels, wastewater tanks in the petrochemical industry, as well as in high-temperature steel manufacturing and other sectors. It is also widely used in fields such as brewing, the food industry, and the pharmaceutical industry. 3. Integrated product design, contactless speaker – no wear and no pollution. 4. The instrument can be configured and edited through user-friendly buttons, the HART protocol, and an operation window; advanced and multifunctional software helps to eliminate interference from mixers or other obstacles. Disadvantages: 1. Most economical pulse-type level gauges use microwave frequencies of 5.8 GHz or 6.3 GHz, which have a large radiation angle (about 30°), resulting in easy generation of interference echoes on the container walls or internal components. Although increasing the antenna size can slightly reduce interference, it leads to a larger size, making it inconvenient to use and maintain. 2. When there are significant fluctuations in the liquid level or dense foam, the measurement conditions become more complex; the signals get scattered and deviate from their path of propagation, or they absorb most of their energy, resulting in weaker signals reaching the antenna of the radar level gauge, or even no signal at all ； 3. When there are obstacles such as agitators or pipes inside the storage tank, these obstacles will also reflect electromagnetic wave signals, thereby generating false level signals. The radar level gauge antennas developed independently by Dinghua Electronics feature small size, a narrow beam angle, and a shorter wavelength, which can perfectly address the problems caused by the aforementioned shortcomings. https://nwzimg.wezhan.cn/contents/sitefiles2057/10285453/images/40329158.png https://nwzimg.wezhan.cn/contents/sitefiles2057/10285453/images/39880553.png If it is not a contactless pulse radar of the “10-minute relationship” type, a guided-wave radar level gauge can be chosen. Guided wave radar is a measuring instrument based on the time-of-travel principle; radar waves travel at the speed of light, and the travel time can be converted into a level signal using electronic components. The probe emits high-frequency pulses that travel along a cable or rod-type probe; when these pulses encounter the surface of the material, they are reflected back and captured by a receiver within the instrument, which then converts the distance signal into a level signal. https://nwzimg.wezhan.cn/contents/sitefiles2057/10285453/images/40329159.png Advantages: 1. It has a strong ability to suppress steam and foam, ensuring that measurements are not affected ； 2. Unaffected by liquid density, the looseness of solid materials, temperature, and dust during feeding ； 3. Low maintenance, high performance, high precision, high reliability, and long service life. Disadvantage: The guided-wave radar level gauge is a contact-type radar; it is not suitable for use when the medium to be measured has high hygiene requirements.