The principle of pipeline flowmeter is used to measure the flow of conductive fluid mechanics of drinking water, steel, crude oil, chemical plant, electric power engineering, industrial production, water conservancy engineering, water administration water source and other units, as well as corrosive conductive liquids such as acid, alkali and salt.

The principle of pipeline target flowmeter is based on the basic law of magnetic effect of Faraday current. In the electromagnetic flowmeter, the conductive medium in the measuring tube is equal to the conductive metal rod in the Faraday experiment, and two magnet coils on the left and right sides cause stable electromagnetic field. When there is conductive medium passing through, it will cause induced voltage. The induced voltage caused by the measurement of two electrical levels inside the pipe. The measurement pipeline shall be protected against electromagnetic induction of hydrodynamics and measurement electric level according to the non-conductive lining (vulcanized rubber, Teflon, etc.).

1. The pipeline type electromagnetic flowmeter is a rate type electromagnetic flowmeter based on the basic law of magnetic effect of Faraday current. On the basis of discussing the basic principle of electromagnetic flowmeter measurement, a LDB type [1] electromagnetic flowmeter is designed according to MSP430F149 single chip microcomputer. The power circuit is based on MSP430F149 single chip microcomputer design, and then the design scheme of power circuit of outfield hardware configuration is simplified to keep the measurement and accumulation of liquid flow. The whole block diagram of the design scheme, part of the hardware configuration power circuit and operation software flow chart are obtained in the original text. The LDB electromagnetic flowmeter designed in this paper has been put into production for a long time. The specific application shows that the design scheme has the characteristics of high precision, low energy consumption and strong credibility. The basic design scheme is considered. Installation regulations:

2. Electromagnetic flowmeter can reasonably bypass the strong power engineering, high-frequency machinery and equipment, strong power main switch machinery and equipment; bypass the hazards of high-temperature pyrogen and radioactive substances, bypass the obvious vibration site and strong erosion of the natural environment, etc., in addition, consider the convenience of installation and maintenance.

3. The pipeline electromagnetic flowmeter has the functions of storing flow data information, power-off time, zero flow time and other various data information and alarms 24 hours a day. Every day, you only need one or two SMS messages to get the 24-hour measurement data information of a measurement point, which can also be set according to the requirements of customers. Using the technology of electromagnetic induction vortex flowmeter and GSM Internet, the early project investment of water flow detection system is only 1 / 3 to 1 / 5 of that of relay station method, and the operation cost of system software is only one to two times of SMS content per day. The service fee of frequency and water and electricity fee and maintenance fee in application are saved.

4. The dynamic display, communication mode and data storage of flow measurement instrument are the key components of the instrument panel. The traditional electromagnetic flowmeter generally adopts LED or Segment LCD in dynamic display, which only displays large numbers, English letters, Chinese characters and some unsmooth pattern designs; in data storage level, information content storage is generally stored by binary method, which is not practical and has small storage capacity; in communication mode, it generally adopts RS232 or RS485, which is not very open.

5. Installation of controller in vertical pipeline

The inflow of steam body shall be from bottom to top. When measuring the steam flow, the metal tube rotameter controller can be installed on the vertical pipe, and the inflow is unlimited. If there is a small amount of liquid in the measured steam body,

When measuring the liquid flow, the liquid inflow should be from the bottom up: it is not easy to attach the liquid net weight to the camera.

6. The controller is installed on the top of the level pipe

No matter what kind of hydrodynamics is measured, the controller can be installed on the top of the level pipe, especially for measuring saturated steam, saturated water vapor and ultra-low temperature liquid,

If the standard allows top mounting, the temperature of fluid mechanics will do less harm to the amplifier.

7. Inversion of the controller in the level pipeline

In general, this installation method is not recommended. This installation method is not suitable for measuring general steam body and saturated steam. Can be used to measure saturated water vapor

High temperature liquid or condition requiring frequent cleaning of piping.

8. Installation of controller on insulated pipe

When measuring high temperature steam, the insulation layer shall not exceed one third of the height width ratio of the support frame.

9. In order to solve the problems mentioned above, an electromagnetic flowmeter with information management, graphical interface and digitalization is developed by using 32-bit armcpu and embedded Linux computer operating system. It adopts TFT colorful liquid crystal display to display the information flow data dynamically, which can display the information flow curve and improve the quality and content of the displayed information; according to JFFS2 system files, it uses the method of document to store the data, and the storage capacity is up to 1MB.