3
Construction and function
Construction:
The housing of the VZ...AL consists of the upper housing
and the lower housing part
.
Inside of the upper housing part, the sensor
or the two sensors (VZ 0.2 AL) are located.
These sensors are connected to the connector plug
on the upper side of the upper part.
Inside of the lower housing part, two gearwheels
are located which are mounted in low-
friction bearings
. The process connections
for inlet and outlet are located on opposite
sides of the lower part.
The electrical connection is performed by using the supplied cable socket
. It is inserted on
the connector plug of the VZ...AL.
Upper housing part.
Lower housing part.
Process connection.
Gear wheels / gear pair.
Bearing.
O-ring.
Sensor.
Connector plug.
Cable socket with pre-amplifier.
Function:
The very precisely adjusted gear pair within the housing forms the measuring element.
The inflowing medium causes the gear pair to rotate.
The rotary motion is scanned without contact by the
sensor or sensors.
The sensor signals are converted via the pre-amplifier
in the cable socket into square wave signals. The fre-
quency of the output signal is proportional to the
measured flow.
Since each individual tooth generates a pulse, this re-
sults in a very high resolution. Consequently, even the
smallest volumes can be measured or dosed precise-
ly.
The VZ 0.2 AL contains two sensors which are offset by
¼ of a tooth pitch. Therefore, the two output signals
are out of phase by ~ 90°.
Suitable processing of the signal provides the detection of the flow direction.
For normal measurements, the reading of one channel is sufficient.
