作为一种目前非常流行的液体测量的流量计。 Ultrasonic flowmeter is a very popular flowmeter for liquid measurement. With the advancement of science and technology, the application of flowmeters in the water supply industry has become more widespread. Therefore, the ultrasonic flowmeter has a great role in the application of the water supply industry, the following Jiangsu Jinhu Dongxiang Instrument Co., Ltd. introduces the application of the ultrasonic flowmeter in the water supply industry. Flow meters are divided into two categories: raw water entering the factory, finished water from the factory, water supply to users, settlement measurement, etc., and internal flow of the water factory, and measurement / control. Prior to the 1950s, traditional liquid turbine flow meters and end-user charge mechanical impeller water meters were used for water production and water supply transfer settlement instruments.
In the application of traditional ultrasonic flowmeters, people often use portable externally clamped ultrasonic flowmeters to compare the flow when measuring, which is very common in the water supply industry. However, relevant problems have arisen in the application. When this method is adopted, the determination of the uncertainty of the measurement system composed of the ultrasonic flowmeter installed on the site should be evaluated. Because the system uncertainty, in addition to the accuracy of the ultrasonic flowmeter itself, should also include the additional errors formed by the measurement deviations of the flow area, the sound path distance, and the sound path angle; Distribution distortion and additional errors caused by swirling flow.
The so-called flowmeter accuracy is actually the accuracy of the measured fluid flow rate. Do not misunderstand or be misled into the accuracy of the measured flow rate. 比对法的总不确定度在2%～5%之间，若加上测量几何尺寸的粗糙或无法获悉确切流通面积的因素，系统不确定度甚至超过5%。 The total uncertainty of the portable ultrasonic flowmeter comparison method is between 2% and 5%. If the measurement geometry is rough or the exact flow area cannot be learned, the system uncertainty is even more than 5%. Most water utilities have noticed more importance than the portable ultrasonic flowmeter installation location and pipe / installation size. After some enterprises set up a new flowmeter, they then compared it with a portable ultrasonic flowmeter and recorded the data for easy analysis in the future.
To ensure the accuracy of the measurement, the installation position or method of the portable ultrasonic flowmeter transducer can also be changed to detect the flow condition of the pipe section on site. For example, move the two transducers along the circumference of the tube to check the average line velocity at different positions. The maximum flow rate may be the position closest to the actual average flow rate, because the flow velocity distortion at the most asymmetric position results in the smallest average flow rate reading. . This is the recommended evaluation method for all published experimental report arguments. Compare the measured flow rates of the transducers installed by the Z method and the V method. If there is a large difference between the two, it indicates that there is serious lateral flow, that is, there are signs of swirling flow. Attention should be paid and corresponding measures taken.
的种类的不断地扩大着，生产出不同类型的超声波流量计那么对于其标准应该是怎样的呢？ The types of ultrasonic flowmeters are constantly expanding, and different types of ultrasonic flowmeters are produced. So what should be the standard for them? To this end, the country has promulgated relevant laws and regulations. There are two methods to check the flow value of the ultrasonic flowmeter: offline check and on-site check. Off-line flow calibration check The instrument is taken off the pipeline and sent to the laboratory flow calibration device for real-flow calibration. However, large-diameter water pipes in the water supply industry are not allowed to cut off the water flow arbitrarily, decommission the flow sensor and implement offline calibration. In practice, each water supply company explores several methods of field comparison or indirect inspection to verify or evaluate the flow according to their respective conditions of use. The flow measurement value of the meter is still maintained or has exceeded the original calibration accuracy level, as a basis for whether it can still be used or needs further inspection.