KROHNE OPTIFLUX 7300 Quickstart EN - Manual (Page 17)

TECHNICAL DATA
4
17
OPTIFLUX 7300
www.krohne.com 01/2011 - 7312082200 - QS OPTIFLUX 7300 R02 en
4.1 Measuring principle
An electrically conductive fluid flows inside an electrically insulated pipe through a magnetic
field. This magnetic field is generated by a current, flowing through a pair of field coils. Inside of
the fluid, a voltage U is generated:
U = v * k * B * D
U = v * k * B * D U = v * k * B * D U = v * k * B * D
in which:
v = mean flow velocity
k = factor correcting for geometry
B = magnetic field strength
D = inner diameter of flow meter
The signal voltage U is picked off by electrodes and is proportional to the mean flow velocity v
and thus the flow rate q. A signal converter is used to amplify the signal voltage, filter it and
convert it into signals for totalising, recording and output processing.
1 Induced voltage (proportional to flow velocity)
2 Electrodes (capacitive)
3 Magnetic field
4 Field coils