Electromagnetic Induction-Based Flow Meter Series For Precise Volumetric Measurements

Overview

The Electromagnetic Flowmeter is an induction instrument for measuring the volumetric flow of conductive media. It provides on-site monitoring and display while outputting standard current signals for recording, regulation, and control. This enables automated monitoring and control, and allows for long-distance signal transmission. The flowmeter is widely used across various industries such as water supply, chemical, coal, environmental protection, light industry, metallurgy, papermaking, etc., for measuring the flow of conductive liquids.

Main Technical Specifications

Working Principle

Based on Faraday's law of electromagnetic induction, a pair of detection electrodes are installed on the walls of the measurement tube, perpendicular to both the axis of the tube and the magnetic lines of force. As the conductive liquid moves along the axis of the measuring tube, it cuts through the magnetic lines, generating an induced electromotive force (EMF). This EMF is detected by the electrodes and is directly proportional to the flow rate, given by the formula:
E = KBVD
where:
E – Induced electromotive force;
K – A coefficient related to the magnetic field distribution and axial length;
B – Magnetic induction strength;
V – Average velocity of the conductive liquid;
D – Distance between electrodes (diameter of the measuring tube).
The sensor sends the induced EMF as a flow signal to the converter, where it is amplified and processed through digital filtering and other processes. The instantaneous and cumulative flow rates are displayed on a backlit dot-matrix LCD. The converter features a 4-20mA output and RS485 communication interfaces, supporting HART and MODBUS protocols.

Features

Simple sensor structure with no moving parts inside the measuring tube, allowing unobstructed fluid flow.
Capable of measuring flow in dirty, corrosive, or suspended solid-liquid two-phase media.
Measurement accuracy is unaffected by the medium's temperature, viscosity, density, and conductivity (within certain limits).
Output is proportional only to the average velocity of the medium, irrespective of the flow profile (whether laminar or turbulent).
Quick response with no mechanical inertia, capable of measuring instantaneous pulsating flow, as well as flow in both directions.
Wide range of industrial flowmeter sizes available.