3.2
Scaling
The scale correction function performs a conversion between the electrical quantities meas-
ured and the physical quantities converted.
This linearization is used partially to correct errors induced by non linear sensor / converter
systems.
The Set to scale function is used to define up to 10 segments of a straight line, or 10 points, in
order to approach a non linear response curve as closely as possible and to perform scale
corrections for each segment.
The
symbol is displayed on the screen in the active window when Set to scale is active.
The
Define…
menu is used to program up to
10 lines with 2 values: X and Y= f(X).
In measurment:
•
X = the value measured,
•
X = the value displayed.
In transmission:
•
X = the setting displayed,
•
Y = the value transmitted.
The lines entered are sorted according to increasing X to set to scale a value X, the unit
searches for the 2 lines n and m=n+1 that enclose it and extrapolates linearly:
Y = Yn + (X-Xn) x (Ym-Yn)/(Xm-Xn)
Use the function keys to edit the points:
•
To add a line:
Enter X and Y, then press the
function key.
•
To select a line from the list, use the Up and Down
navigation keys.
•
To cancel a selected line, use the
key.
The Format and Units zones are used to select the number of decimal places and the display
units.
