Siemens SITRANS T4200, Operating Instructions Manual

Page: 54 / 100

Functions
9.14 Current sensor calibration (digital-to-analog trim)
SITRANS TH200/TH300
Operating Instructions, 06/2010, A5E00393069-03
53
9.14 Current sensor calibration (digital-to-analog trim)
9.14.1 Function
This function allows you to calibrate the current output by the transmitter regardless of the
sensor circuit. This function allows compensation of inaccuracies in the process chain
downstream from the transmitter. The trim can only be performed as follows:
● Device version 200: at 4 mA and at 16 mA
● Device version 300: at 4 mA and at 20 mA
The following figure shows the principle of trimming using the example of the 4 to 20 mA
current output.
0HDVXUHG
FXUUHQW,
1RPLQDO
FXUUHQW,
P$ P$
$
%
&
,
,
O Output characteristic
①
A→B: Parallel offset
B Characteristic curve after current transmitter
trim 4 mA
②
B→C: Change in gradient
C Characteristic curve after current transmitter
trim 20 mA
Figure 9-3 Current transmitter trim
See also
Application example: Current input calibration at 4 mA and 20 mA (Page 54)