LDG-200S electromagnetic flowmeter in the field of water supply applications

Case introduction

LDG-200S electromagnetic flowmeter application is in 1832, our junior high school physics have learnt, the law of electromagnetic induction is 1831 physicist Faraday found, and the first human use of the principle of electromagnetic induction to measure the flow is also carried out by Faraday. When he was in the Thames Waterloo Bridge on both sides of the river, choose and the direction of the flow of water perpendicular to the direction of the geomagnetic field of the place, put down two metal rods as electrodes to measure the flow rate of the river, which is human civilisation and science and technology is a great creation. In the modern field of industrial measurement, the use of electromagnetic flowmeter has been very common, a variety of new materials and new technologies and electromagnetic flowmeter combination is also increasingly close, but the electromagnetic flowmeter has its advantages and disadvantages, we choose its products, to be familiar with its working principle and measurement advantages, this paper focuses on the water company electromagnetic flowmeter selection of management, and will introduce the electromagnetic flowmeter of the telemetry monitoring Management methods, the use of the flowmeter in the process of problems, put forward their own views and suggestions. LDG-200S electromagnetic flowmeter selection flowmeter measurement accuracy, costing of enterprises, energy consumption and other important indicators of the calculation will have a greater impact, it is the choice of stable operation, quality assurance, measurement of accurate flowmeter is extremely important. With the development of science and technology, more and more varieties of flowmeter, performance varies, technical parameters and conditions of use are also different, so the selection should be the first to understand the performance characteristics of the flowmeter and combined with the use of the unit's operating conditions.1.1 Comparison of the characteristics of several types of flowmeter: Electromagnetic flowmeter 1, impeller flowmeter: impeller flowmeter working principle is to place the impeller in the measured fluid, the impact of the flowing fluid and rotate! The impeller rotation speed to reflect the size of the flow. Impeller flowmeter mainly water meter and turbine flowmeter, the output mode has mechanical transmission or electrode impulse two kinds. Mechanical transmission output of the water meter accuracy is low, the error is about ± 2%; electrode impulse signal output of the turbine flowmeter accuracy is high, the general error is ± 0.2% - 0.5%. 2, electromagnetic flowmeter: electromagnetic flowmeter is based on Faraday's law of electromagnetic induction, that is, conductive liquid in the magnetic field cutting magnetic lines of force movement, the conductor produces induced electromotive force, and the induced electromotive force and the magnetic field, Flow size is proportional to the measurement of electric potential to reflect the principle of pipeline flow and made. There are mainly two types of pipeline and insertion type. Pipeline accuracy level of ± 1.5% - ± 2.5%, accuracy of ± 0.5% - ± 1.0%; insertion type accuracy of ± 1.5% - ± 2.5%. Due to the defects in the structure of the insertion and installation errors will affect the measurement accuracy, so the choice of pipeline better. 3, ultrasonic flowmeter: ultrasonic flowmeter is based on ultrasonic propagation speed in the flow medium is equal to the average flow rate of the measured medium and the speed of the acoustic wave itself and the geometric velocity of the design principle. Doppler ultrasonic flowmeter and time-difference ultrasonic flowmeter, more than the current time-difference ultrasonic flowmeter. According to the use of different occasions, can be divided into fixed ultrasonic flowmeter and portable ultrasonic flowmeter. Fixed acoustic flowmeter is divided into external clamping, insertion type, pipe section type three. Fixed ultrasonic flowmeter due to some pipeline material loose, wall thickness is not the same, poor acoustic conductivity or corrosion is serious, the lining and the pipe wall has a gap and other reasons, resulting in serious attenuation of ultrasonic signals. Flowmeter selection of the basic requirements: 1, the flowmeter accuracy to a stable operation. 2, the pressure loss of water is small. 3, if the user changes in water consumption or the distribution of water is very uneven, the requirements of the flowmeter range ratio to be larger. 4, the sensitivity should be high to meet the low flow rate of measurement of the accuracy of the 5, the flowmeter on-site conditions should not be too sensitive. 6, according to the needs of the selection of the flowmeter can be measured in positive and negative directions. 7, operation, reliable, durable, and maintenance. Reliable, durable, easy maintenance.