Siemens SITRANS P DS III Operating Instructions Manual page 131

Example of an application
The current is to be measured as a voltage drop from 1 to 5 V at a resistance of 250 Ohm +/-
5%. To trim the tolerance of the resistance, set the current transmitter so that the voltage
drop at 4 mA is exactly 1 V and at 20 mA is exactly 5 V.
● Trim at 4 mA:
● Trim at 20 mA:
SITRANS P DS III with HART
Operating Instructions, 06/2013, A5E00047092-09
Use the current transmitter trim menu option to instruct the transmitter to output 4 mA.
Read the measured value at an ammeter and input it. The transmitter uses this value for
offset correction of the current.
Use the current transmitter trim menu option to instruct the transmitter to output 20 mA.
Read the measured value at an ammeter and input it. The transmitter uses this value for
gradient correction of the current. The value for 4 mA is not affected by this.
Note
If a multimeter is used, it must always be sufficiently accurate.
A Original characteristic
B Characteristic curve after current transmitter trim 4 mA
C Characteristic curve after current transmitter trim 20 mA
Figure 7-15 Current transmitter trim
Operating functions through HART
7.17 Current sensor trim
131