3
Construction and function
The two main components of the VO are the measuring chamber housing and the display
unit. Measurement is performed in the measuring chamber housing. The pulses generated
there are evaluated in the display unit and displayed as a volume or flow value on the LCD
display.
The display unit has its own housing and is mounted on the measuring chamber housing. Op-
tionally, the display unit may also be placed on the wall, offset from the measuring chamber
housing.
Construction (mechanical):
The VO consists of measuring chamber housing
with two pivoted oval wheels
.
The gear teeth of the two high-precision internal
gears mesh. Through these gear teeth and the
slight contact to the measuring chamber wall, the
input side
is separated and sealed from the out-
put side
.
Between the individual oval wheels and the adjacent
measuring chamber wall, a movable measuring
chamber
is formed, with a defined partial vol-
ume.
Function:
The oval gear flow meter of the series VO belongs to the group of direct volumetric meters
with movable partition walls.
The flow of medium drives the two oval wheels, and they roll over and away from each other
in opposite directions.
The measuring chambers formed by the oval wheels
thus move from the input to the output side. For each
revolution of the oval wheels, two partial volumes each
(i.e. a total of four) are transported through the VO
(
see figure).
The rotary motion of the oval wheels is transmitted to
a sensor element via magnets. The number of revolu-
tions is directly proportional to the flow rate.
The output signal of the sensor is evaluated by the
electronics and shown in the display.
