BA_072_2020-02_10.00 Pressure transmitter PASCAL Ci4
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6.4.5.3 Output function
You can set the output function proportionally rising to the measured value (selection "Lin-
ear") or proportionally falling (selection "Inverse"). You can also define the output signal by
a table with interpolation point, e.g. to represent a tank shape (selection "Table").
There is also a square root output function implemented for flow measurement per differ-
ential pressure (selection "Square root"). In this case the differential pressure is propor-
tional to the square of the flow. When you select the square root output function the output
signal is proportional to the flow value. As usual the first 6% of the measuring range are
approximated by a linear section.
6.4.5.4 Setting the measurement range
You can freely set the lower and upper range value within the nominal range of the device,
as long as the set range is not smaller than 1% of the nominal range (turndown 100:1).
Please note that when the turndown is increased, the measurement error also increases. If
you use a very small range you must therefore accept a significant measurement error.
We recommended a maximum turndown of 10:1.
The lower range value must be below the upper range value. For an inverse characteristic
curve, select the output function setting “inverse”.
6.4.5.5 Configuration of the table function
With the table function you can realise any output function. E.g. you can convert the fill
height to the fill quantity depending on the tank shape. You can use up to 64 interpolation
points for this purpose.
We recommend the use of a PASCAL Ci4 LEVEL device for fill level applications. Its oper-
ating software has been specially optimised for fill level applications.
Menue entry
Description
Number of points
Number of interpolation points
Table values
Combination of pressure in per cent and corresponding current
value that are used as interpolation points of the table function
Table 14: "Output Table" submenue
You can only edit the table points when the table function is not active. You may need to
set the output function to "linear", for instance (see above) before editing table points.
The table points must be sorted according to ascending pressure. For instance, the 20%
point may not be before the 10% point. Otherwise you cannot activate the table function.
If the first table point is not set at 0%, the start of the table is calculated by means of the
first two interpolation points. The same applies when the last table point is not at 100%.
With the
- and
- buttons, you can scroll through the table points and look at the
combinations of pressure in per cent and current in mA. With OK, you switch to the edit
mode for the displayed table point. Now enter the first per cent value and then the current
value. When you confirm the current value, you return to the display of the table point you
just edited.
