Electromagnetic Flowmeter

Overview

The LDDC electromagnetic flowmeter consists of two parts: a sensor and a converter. It works based on Faraday's law of electromagnetic induction and is used to measure electrical conductivity

High rateIn 5MThe volumetric flow rate of S/cm conductive liquid is an inductive instrument used to measure the volumetric flow rate of conductive media. Except for measurable general conductive liquids

volumeIn addition to flow rate, it can also be used to measure the volume of strong corrosive liquids such as strong acids and alkalis, as well as homogeneous liquid-solid two-phase suspensions such as mud, slurry, and pulp

Traffic. wideWidely applied to industrial sectors such as petroleum, chemical, metallurgical, textile, papermaking, environmental protection, food, as well as municipal management, water conservancy construction, and river dredging

Jun and other fieldsTraffic measurement.

Measuring principle

According to Faraday's principle of electromagnetic induction, a pair of detectors are installed on the pipe wall perpendicular to the axis of the measuring tube and the magnetic field linesElectrode, as a conductive liquid

When moving along the axis of the measuring tube, the conductive liquid cuts the magnetic field lines and generates an induced potential, which is generated byTwo detection electrodes are used to detect, and the numerical value is related to the current

Proportional in quantity,

Its value is:

E=KBVD

In the formula: E-induced potential; D-electrode spacing; (Measuring the inner diameter of the tube)

B-Magnetic induction intensity; V-average flow velocity of conductive liquid;

K - Coefficient related to magnetic field distribution and axial length.

The sensor uses the induced electric heat E as a flow signal, which is transmitted to the converter. After amplification, transformation filtering, and a series of digital processing, it is used with backlightof

Dot matrix LCD displays instantaneous and cumulative flow rates. The converter has 4-20mA output, upper and lower limit alarm output, and frequency output, and is equipped with RS-485, etc

Hart protocol for communication interface.

Instrument features

There is no obstruction in the measuring tube, and the pressure loss is zero, making it difficult to block.

●As long as the electrode and lining materials are selected reasonably, the requirements for corrosion resistance and wear resistance can be achieved.

●The measurement results are basically independent of physical parameters such as pressure, temperature, density, viscosity, and conductivity (not less than conductivity) of the liquid, and are not affected by the environment

Due to its impact, the measurement accuracy is high, the work is stable, and reliable.

●By adopting modern analog signal conversion technology and high-performance ultra large scale integrated chips, signals are isolated, filtered, amplified, and digitally processed. Precision

Clearly visibleDisplay the measurement results.

●Automatically monitor and correct parameters that affect measurement results, such as zero drift correction, and set and correct segmented flow coefficients for the entire range

ButExpanded the measurement range, improved the level of intelligence and measurement accuracy, greatly enhancing stability performance.

●Equipped with measurement power-off protection and over range alarm function, it can set the flow direction of the fluid inside the sensor, so the installation of the sensor is not affected by liquid flow

moveDirectional restriction enables bidirectional flow measurement.

●Adopting a backlit dot matrix dual row flow display, it can simultaneously display instantaneous flow, cumulative flow, and display working status, parameters, and measurement units

Wait.

●The range of electromagnetic flowmeter is wide (flow rate/minimum flow rate), with a normal application range of 20:1, generally 30:1 or larger.

●The instrument configuration has multiple output functions and can be matched with computers and unit combination instruments to meet the requirements of printing, communication, and networking.

●Flow meters generally have a medium flow rate of 2-6 meters per second, and for special cases, it should not be less than 0.3 meters per second and not exceed 12 meters per second. If the flow rate is too high

Low, electricityThe decrease in magnetic signal leads to a decrease in measurement accuracy. If the fluid contains solid particles, the flow rate should be kept below 3 meters per second. For viscous liquids,

Corresponding flowQuick accessA higher value helps to automatically eliminate dirt on the electrode and also improves measurement accuracy.

The calculation formula for the relationship between flow rate, flow velocity, and caliber:

Among them: Q=flow rate (meters)³/Hour)

V=flow velocity (in meters)/Seconds)

D=caliber (meters)）

After determining the diameter of the flowmeter, it should be increased (15%~30%) to the full range value according to the preset process flow rate. In practical use, traffic

allIt shall not exceed the full-scale value. If it exceeds the full-scale value, the flow error in that part shall be significant, and the normal accuracy range between the full-scale and minimum flow shall not exceed

pass20Twice.