Vega VEGABAR 87 Operating Instructions Manual page 34

6 Set up with the display and adjustment module
Current output (mode)
Current output (min./
max.)
Lock/Unlock adjustment
34
With flow measurement and selection "Linear" display and output
(percentage/current) are linear to "Differential pressure". This can
be used, for example, to feed a flow computer.
With flow measurement and selection "Extraction by root"display and
output (percentage/current) are linear to "Flow".
With flow in two directions (bidirectional) a negative differential pres-
sure is also possible. This must already be taken into account in menu
item "Min. adjustment flow".
Caution:
Note the following, if the respective sensor is used as part of an over-
fill protection system according to WHG:
If a linearisation curve is selected, the measuring signal is no longer
necessarily linear to the filling height. This must be considered by the
user especially when setting the switching point on the limit signal
transmitter.
In the menu item "Current output mode" you determine the output
characteristics and reaction of the current output in case of fault.
The default setting is output characteristics 4 ... 20 mA, fault mode
< 3.6 mA.
In the menu item "Current output Min./Max.", you determine the reac-
tion of the current output during operation.
The default setting is min. current 3.8 mA and max. current 20.5 mA.
In the menu item "Lock/unlock adjustment" you safeguard the sensor
parameters against unauthorized or unintentional modifications.
With active PIN, only the following adjustment functions are possible
without entering a PIN:
The device assumes an approximately constant temperature and static
1)
pressure and converts the differential pressure into the flow rate via the
characteristic curve extracted by root.
1)
VEGABAR 87 • 4 ... 20 mA