Burkert 8756, Operating Instructions Manual

Page: 57 / 88

Type 8756
Setting and operation
english 57
Operating mode Description
Open-loop control mode Refer to chapter: Choose the
source that gives the set-point
value (MFC) [
} 60]
Analyze system Refer to chapter: Choose the
source that gives the set-point
value (MFC) [
}
60]
Tab. 65: Names of the operating modes of an MFC in the Bürkert
Communicator software
To change the operating mode, change the source for the set-
point values. Refer to chapter:
Choose the source that gives
the set-point value (MFC) [
}
60]
The operating mode is kept after a product restart, except when
the product performs the function
Analyze system .
8.7 Normal operating mode (MFC)
The normal operating mode is active when energising the product
for the first time.
The following figure shows the normal operating mode of an MFC
with pump.
Electronics
Sensor Pump
Fluid inlet
Fluid outlet
w
Xout
xd = w-x
y
x
Fig. 28: Function diagram of the MFC with pump
w set-point value of the mass flow rate
x measured value of the mass flow rate
y set-point position of the pump
The following figure shows the normal operating mode of an MFC
with control valve.
If the valve seat seal is made of a hard material such as
PCTFE, then the control valve may not be tight.
Products with a nominal valve diameter of 0.05 mm or 0.1
mm have a valve seat seal made of a hard material.