Thermometers To The Sm 331; Ai 8 X Tc - Siemens SIMATIC S7-300 Reference Manual

Connecting thermocouples with resistance thermometer to the
SM 331; AI 8 x TC
With this type of compensation, the reference junction terminal temperature is
determined by a bulb resistor sensor with a temperature range of -25 °C to 85 °C.
Thermo-
couples
Compensating
leads (same
material as
thermocouple)
Figure 4-27 Connecting thermocouples with external compensation via resistance thermometers to the
SM 331; AI 8 x TC
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
Copper
wire
K0
K7
Pt 100
Ref. junction
KV+
KV–
ADC
KV+
KV–
KV+
KV–
IC
+
IC
–
Analog Modules
L+
M
P5V
Backplane
bus
M internal
4-65