In this case, the MC 75.2 supplies a passive transmitter with 24 V and at the same time
measures the current established by the transmitter.
If the loop power supply is off, the connection is made between terminals mA and COM.
When set to the square law scale, the calibrator takes the square root of the input and dis-
plays the result as a percentage. For example, if the calibrator is connected to the output of a
differential pressure transmitter, it displays a result proportional to the flow rate.
If the input current x varies between a and b, the scale is set according to the formula:
(
) (
)
(
)
a
b
a
x
a
b
a
y
−
−
−
+
=
In the case of the 0-20 mA range, the scale curve is as follows:
