Electromagnetic Flowmeters, Commonly known as Magmeters are a type of inferential flow metering devices used to measure the flow of electrically conductive liquid in closed pipe applications where the magnetic flux permeates the entire cross sectional area of the liquid flow. Magmeters measure electromotive force to determine liquid velocity using Faraday's Law of Electromagnetic Inducation and compute the flowrate using the equation of conductivity.
Eureka make Eumag Flowmeters operate with electrically conductive liquids and are relatively immune to the effects of Pressure, Temperature, Density & Viscosity of the liquid medium. For Eumag Flowmeter the electrically conductive liquid is defined as a liquid with a Conductivity of at least 5 Micro Siemens/Cm.
Principle of Operation
Faraday's law states that when a conductor moves through a magnetic field of a given strength, a voltage is produced in the Electrode dependent on and proportional to the relative velocity between the conductor and the magnetic field.
The mathematical representation is as follows:
U = B x V x D x C
U = Induced Voltage
V = Average Velocity
D = Internal Dia. of Flow Tube
C = Instrument Constant
B = Magnetic Field Strength
The flowrate equation is
Q = VA
V = Average Velocity
A = Area occupied by the flow
Eumag Flowmeter consist of a Sensor and Convertor.
The Sensor consist of a measurement Flow Tube section, non conductive Liner, Electrodes & Coils. The Flow tube Sensor, is made of material that is permeable to magnetic flux, such as SS 304, or SS316, or other nonmagnetic material. The inner surface of the Flow Tube is lined with nonconductive material to insulate it from the process liquid. This prevents the voltage generated by the velocity of the flowing media, from shorting out on the
measurement section & allows the Electrodes to detect the voltage.
The Electrodes are made of SS316 or an alloy with high nickel content such as Hastelloy.
The voltage detected by the Electrodes is amplified and processed by an electronic Transmitter which outputs an electrical signal proportional to the fluid flow rate, and powers the coils generating the magnetic field. This microprocessor based Transmitter, commonly known as Convertor, can be equipped with a LCD for flow rate indication and the programming of all important parameters such as Output Signal, empty pipe etc. This convertor can be mounted on the sensor or remote.
Specifications For Series Eumag--0/1
Basic Flowmeter Sensor
|Accuracy||:||+0.5%, +1%, +2% of flow rate|
|Liquid Conductivity||:||5 Micro Siemens or better|
|Line Size||:||4 NB to 1600 NB|
|Pressure Rating||:||Upto 40 bar|
|Temperature Rating||:||600 C for Neoprene lining, 1800 C for PTFE lining|
|Lining Material||:||Neoprene, PTFE other on request|
|Electrode Material||:||SS 316, SS 316 L, HASTELLOY-C, Titanium other on request|
|Protection Category||:||P 65(Optional IP-67, IP-68)|
|Earthing Electrode||:||Built in (no need for earthing rings)|
|Velocity Ranges||:||Progrmmable 0+2.5 m/s, 0+5 m/s 0+10 m/s|
|Accuracy||:||+0.5% of Flow Rate or better in between 0.5 to 10m/sec. velocity|
|Supply Voltage||:||110/220 VAC, 50HZ optional - 24 VAC or 24 VDC|
|Programmability through MMI or Serial Port||:||Pipe Diameter, Flow Units, Pulse Output Units and Resolution, Low-flow Cut-off percentage, Bidirectional Flow.|
Convertor with inputs display:
Apart from the above features, it has isolated RS 485 or RS 232 or HART capability. It also includes the Batching option, Logging option etc.
- 16x2 Backlit Display (ch. Size 3 mm)
- 6 Key Membrane Keyboard
- Serial Interface with basic MF board
- Serial Interface to field: RS 485 Galvanically Isolated for Modbus / Profibus Options
- Batching capability
- Operator Menu based Interface For Setting Up and Servicing.
Note: At any given time only one of the interfaces can be offered : RS 485 or Rs 232 or HART
- High accuracy & stable performance
- No moving parts
- Easy installation and operation
- Minimal maintenance
- Microprocessor based designs offering exceptional configuration flexibility
- Basic model has isolated current output
- Programmable through PC by serial port even in basic model
- Easy programmablility using key board on Alpha numeric display
- Configutation personality stored in a pluggable personality module
- Advanced model having advance features of: RS 485 communication, HART, Batching, special parameter indications of pressure, temperature and energy metering like heating/cooling
- Compact and rugged, IP 65 protection class
- The display can be rotated in desired angle to offer ease in viewing
- Converter can be mounted away from the sensor