Electromagnetic Flowmeter
Volumetric flow measurement for conductive liquids, built to JB/T 9248 and explosion-proof certified for hazardous area duty. Local indication is paired with a standard current output for recording, control and remote transmission.
0.5%
Accuracy Class
1.6 MPa
Pressure Rating
IP65
Protection
Exd IIC T6
Explosion Protection
DEFINITION & OVERVIEW
What is an Electromagnetic Flowmeter?
An electromagnetic flowmeter measures the volumetric flow rate of conductive liquids slurry water, process water, and similar streams throughout a coal washery without any moving parts in the flow path. This makes it well suited to the wet, particle-laden duty common across a washery's slurry water circuit, where mechanical flow meters wear or clog.
John Finlay's unit is built to JB/T 9248 and carries Exd IIC T6 explosion protection, meaning it's certified for installation in hazardous areas where flammable atmospheres are a design consideration, not just a general industrial rating.
An integral digital indicator with a calibratable span and zero displays both real-time and totalized flow directly at the instrument, while a standard 4–20 mA and RS485 output feeds the same data to recording, control, and remote monitoring systems.
How It Works
Measures volumetric flow of conductive liquids electromagnetically, with no moving parts in the flow path to wear or clog.
Explosion-Proof Rated
Exd IIC T6 certification supports installation in hazardous area duty, not just general industrial environments.
Local and Remote Reading
Integral digital indicator shows real-time and totalized flow on-site, with 4–20 mA and RS485 output for SCADA integration.
Parameter | Value |
|---|---|
Accuracy | 0.5% |
Pressure Rating | 1.6 MPa |
Protection | IP65 |
Explosion Protection | Exd IIC T6 |
Lining | Polyurethane |
Body Material | 304 stainless steel |
Electrodes | Stainless steel / tungsten carbide, high frequency |
Output | 4–20 mA and RS485 |
Installation | Flanged; integral or remote converter |
KEY FEATURES
Key Features & Performance Highlights
Built specifically for continuous, conductive-liquid duty in a coal washery slurry water circuit, not adapted from a general industrial flowmeter line.
Polyurethane Lining and Stainless Body
A polyurethane-lined measuring tube in a 304 stainless steel body resists the abrasive, particle-laden conditions typical of washery slurry water, while stainless steel/tungsten carbide high-frequency electrodes hold measurement stability under continuous duty.
Explosion-Proof Certification
The Exd IIC T6 rating and JB/T 9248 compliance mean the unit is certified for hazardous area installation, an important distinction from general-purpose flowmeters that carry only a standard IP rating.
Calibratable Integral Indicator
The integral digital indicator has a calibratable span and zero and displays both real-time and totalized flow directly at the instrument, which is useful for field verification without needing to reference a remote control room reading.
WORKING PRINCIPLE
How the Electromagnetic Flowmeter Works
Electromagnetic flow measurement depends on the conductive liquid itself, not a mechanical sensing element.
Conductive Liquid Flow
The flowmeter is installed in line, flanged into the slurry water or process water piping it's measuring.
Electromagnetic Induction
As the conductive liquid flows through the measuring tube, it generates a voltage proportional to its velocity, which is sensed by the high-frequency stainless steel / tungsten carbide electrodes.
Signal Processing
The integral electronics convert this signal into a volumetric flow rate, which can be calibrated for span and zero to maintain rated accuracy.
Local Display
Real-time and totalized flow are shown directly on the integral digital indicator, viewable at the instrument without a separate control room reading.
Signal Output
A 4–20 mA and RS485 output feeds the same flow data to recording, control, and remote transmission systems simultaneously.
TECHNICAL SPECIFICATIONS
Electromagnetic Flowmeter | Full Specification
Specifications sourced directly from John Finlay’s instrumentation documentation.
Parameter | Value |
|---|---|
Standard | JB/T 9248 |
Accuracy | 0.5% |
Pressure Rating | 1.6 MPa |
Protection | IP65 |
Explosion Protection | Exd IIC T6 |
Lining | Polyurethane |
Body Material | 304 stainless steel |
Electrodes | Stainless steel / tungsten carbide, high frequency |
Output | 4–20 mA and RS485 |
Installation | Flanged; integral or remote converter |
COMPARISON
Electromagnetic vs. Mechanical Flow Measurement
Electromagnetic Flowmeter
Mechanical Flow Measurement (Typical)
Applications of the Electromagnetic Flowmeter
Electromagnetic flow measurement is used throughout a coal washery's slurry water and process water circuits wherever conductive liquid flow needs continuous, reliable measurement.
Slurry Water Circuit Monitoring
Measures conductive slurry water flow continuously without wear from suspended particles.
Process Water Balance
Supports water balance calculations across the plant by giving accurate, continuous flow data at key circuit points.
Hazardous Area Installations
The Exd IIC T6 certification supports installation in areas where flammable atmosphere considerations apply.
SCADA-Integrated Flow Monitoring
4–20 mA and RS485 output integrate directly into existing plant automation and control systems.
Paired with Density Instrumentation
Flow and density measurements together support the mass balance calculations used in dense medium circuit diagnostics.
Retrofitting Existing Piping
Flanged installation with integral or remote converter options supports fitting into existing pipe runs.
About John Finlay
Flow Measurement Instrumentation Supplier in India
Why John Finlay?
0.5%
Measurement Accuracy
Held via a calibratable span and zero on the integral digital indicator.
130+
Coal Washery Projects
Completed EPC projects worldwide, including Asia’s largest coking coal washery at 30 MTPA.
EPC
Full Circuit Supply
Supplied as part of a complete instrumentation and automation offering, integrated with density and process control instrumentation.
IN
India-Based Support
Manufactured at Hefei John Finlay Mining Equipment Co., Ltd. and supported locally in India for installation, commissioning, spares and service.
Electromagnetic Flowmeter | Frequently Asked Questions
Common questions from engineers in coal washery processes evaluating electromagnetic flow measurement.
This flowmeter can measure any conductive liquid, including slurry water, process water, and similar streams commonly found in a coal washery. It is not suited to non-conductive fluids, which is a limitation of electromagnetic flow measurement generally, not specific to this unit.
Yes, it carries Exd IIC T6 explosion protection and is built to JB/T 9248, supporting installation in areas with flammable atmosphere considerations.
The unit has 0.5% accuracy, with a calibratable span and zero on the integral digital indicator to maintain that accuracy over time.
No. Electromagnetic flow measurement has no moving parts in the flow path, which is a specific advantage in handling slurry water with particles. This technology connects where mechanical flow meters wear or clog.
The unit outputs both 4–20 mA and RS485 signals, integrating directly into existing plant SCADA or control systems alongside the integral local digital display.
Not sure which flow points in your circuit need instrumenting?
Our engineers can help you identify where continuous flow measurement would give you the most useful data.
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