Annex; Design And Measuring Principle - bürkert 8045 Bedienungsanleitung

7.1 DESIGN AND MEASURING PRINCIPLE

Design
The 8045 compact flow transmitter combines a flow sensor and a transducer with dis-
playwithin a splash-proof IP65 plastic enclosure.
The base of the sensor finger contains a solenoid and 2 electrodes which are in contact
with the fluid to detect the induced voltage.
The electronic module converts the induced voltage into a flow value which can be
displayed.
The transducer uses a 3-wire circuit and requires a power supply of 18-36 VDC. The
output signals are provided via one or two cable glands.
For additional control adjustable relays can be used (optional).
Measuring Principle
According to the induction law, a voltage is induced when a conductor is present within
a magnetic field. The space between the 2 electrodes is filled with the conductive fluid
creating a conductor.
Through movement of the conductive fluid (min 20μS/cm) perpendicular to the magne-
tic field which is provided by the solenoid produces a proportional voltage to the flow
velocity.
This voltage is detected between the electrodes and is then converted and filtered
according to the K-factor selected.
The flow direction generates a positive or a negative value of the flow. The magnetic flow
transmitter 8045 measures a flow velocity from 0.1 m/s (0.3 ft/s).
A 4-20 mA standard signal, proportional to the flowrate is available as an output signal.
In case of electronic failure a 22 mA signal is provided.
Pipe
8045

ANNEX

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