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SITRANS T measuring instruments for temperature
Transmitters for rail mounting
SITRANS TW
four-wire system, universal, HART
Schematics
Sensor input connections
1
4
3
3
R, RTD
5
4
3
+
-
TC
9
4
3
-
+
-120 ... 1000 mV
12
4
3
U+
U-
+
-
-1,2 ... 10 V
Resistance thermometers, resistance-based
sensors, potentiometers:
1
Two-wire system; resistance can be
parameterized for line compensation
2
Three-wire system
3
Four-wire system
4
Difference/mean-value circuit; 2
resistors can be parameterized
for line compensation
Connection diagram for the input signal
Channel 1 is the measured variable between the terminals 2 and 3 on the input plug. With a difference or mean-value circuit, the
calculation of the measured value is defined by the type of measurement. Otherwise the measured value is determined via channel
1. The following code is used for the type of measurement:
Type of measurement
Single channel
Differential connection 1
Differential connection 2
Mean-value 1
3/48
Siemens FI 01 · 2010
2
2
1
4
3
R, RTD
6
4
3
2
1
-
TC
10
4
3
2
1
-
13
2
1
4
3
I+
7NG3092-8AW
-12 ... 100 mA
Thermocouples:
5
Determination of cold junction temperature using
built-in Pt100 or fixed reference temperature
6
Determination of cold junction temperature using
external Pt100; resistance can be parameterized
for line compensation
7
Determination of cold junction temperature using
cold junction terminal 7NG3092-8AV
8
Difference/mean-value circuit with internal cold
junction temperature
Calculation of measured value
Channel 1
Channel 1 - Channel 2
Channel 2 - Channel 1
½ ⋅ (Channel 1 + Channel 2)
© Siemens AG 2009
3
2
1
4
3
R, RTD
7
2
1
4
3
+
Pt100
4
-
11
2
1
4
3
-
+
2
1
I-
+
-
The short-circuit jumpers shown in the circuits must be inserted
in the respective system on site.
4
2
1
4
R2, RTD2
8
2
1
4
Pt10
1
+
7NG3092-8AV
TC
2
1
+
Further sources:
9 mV sources with two-wire system
(7NG3242-xxxx0)
10 V sources with two-wire system
(7NG3242-xxxx[1-3])
11
mA/mA sources with two-wire system
(7NG3242-xxxx[4-8])
12 Voltage measurement -1,2 to 10 V with U/I
plug 7NG3092-8AW (7NG3242-xxxx0)
13 Current measurement -12 to 100 mA with
U/I plug 7NG3092-8AW (7NG3242-xxxx0)
3
2
1
R1, RTD1
3
2
1
-
+
TC1
+
TC2
-
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