Irrigation
IOM
Sensors
| 9 |
2 PRODUCT DESCRIPTION
2.1 OPERATING PRINCIPLE
The electromagnetic sensor is used to measure the flow rate of liquids (drinking water, wastewater, beverages,
fertilizers, chemical products, and any other liquid) that have an electrical conductivity of at least 5μS/cm.
Electromagnetic flowmeters are the best solution for measuring the flow rate liquids because of fast response
times, great measurement accuracy, and a passage tube that does not present any obstruction to the liquid
flow, therefore no pressure drop in the pipe. Furthermore, since they do not use any moving parts, they require
virtually no maintenance.
EUROMAG electromagnetic flowmeters cover a wide variety of applications (e.g., water flowmeters, wastewater
flow measurement, fertilizer flow measurement, etc.) and respond to every customer request thanks to the wide
range of models. Meters are available in wafer, flanged, threaded, and insertion versions from DN6 to DN2000
in pressure class up to ANSI900.
In order to perform its measuring function, the sensor must be combined with a converter.
The converters are designed to meet all the needs of modern water management systems through flexible and
hybrid electronics, which, depending on the model, offers various electrical power solutions.
At the ends of a conductive fluid that moves with speed v in a
magnetic induction field
B
an electromotive force e is induced
and can be expressed as:
e = kBDv
Where:
B
B is constant by construction;
D
is constant and represents the distance
between the electrodes
E1
and
E2
(equivalent
to the flowmeter diameter);
v
is the speed of the liquid;
k
is the calibration constant;
The electromotive force «e» is proportional to the speed «v»
2.1.1 Bidirectional reading
The sensor has a possibility of bidirectional reading (i.e., it is able to read the flow of the liquid in both directions).
By convention, the sensor will output positive values if the liquid flows:
in the same direction as the arrow (enters in – and exits in +), the flow is positive, and the display will show
a reading without a sign
in the opposite direction to that indicated by the arrow (enters in + and exits in -), the flow is negative, and
the display will show a reading with a negative sign
Direct flow -> number without sign
Reverse flow -> negative number
1
- Electromotive force (proportional to the speed);
2
- Electrodes;
3
- Magnetic field;
4
- Coils;
2
3
1
4
