Instruction Manual
DM04
3
Construction and function
Components:
Housing:
The housing consists of aluminium die casting and
has the IP65 degree of protection.
Electrical connection:
The electrical connection is made via 5-pin plug
M12x1.
Operation / flow indicator LED.
Process connection:
The process connections are available in different
sizes.
Type plate (sticker).
Construction:
The measuring tube with its earthing sleeves and electrodes passes through the
housing and forms the external process connection of the DM04.
A magnetic field for the measurement process is generated inside the sensor hous-
ing, which also contains the sensor and signal conditioning circuitry.
The two stainless steel electrodes are located in the middle of the measuring tube
between the earthing sleeves.
The DM04 does not need any moving parts to make measurements. The inside of
the measuring tube is completely open, allowing the fluid to flow unhindered
through the measuring tube.
Function:
The magnetic inductive flow sensor operates in accordance with the principle of induction, i.e. a DC voltage
is generated by the movement of a conductor in a magnetic field:
The measuring tube of the DM04 is located in a magnetic
field (B).
An electrically conductive liquid (Q) flows through the measur-
ing tube. The positive and negative charge carriers are deflected
in opposite directions.
A voltage perpendicular to the magnet field is generated and
picked up by the two electrodes.
The resulting induced voltage is proportional to the mean flow
velocity of the liquid.
The electronics of the DM04 converts the induced voltage to a
flow-proportional frequency signal.
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PKP Prozessmesstechnik • 08/2019
