Siemens SITRANS T3K PA 7NG3213, Руководство пользователя

Страница: 32 / 72

Instruction Manual 7NG3213
86
SITRANS T3K PA
C79000-B7174-C55-03
Thermocouples
Determining the comparative tem-
perature with built-in Pt100 or external
reference temperature
Determining the comparative
temperature with external Pt100;
resistance programmable for line
compensation
Millivolt transmitter
Difference/averaging circuit
with internal comparative temperature
Two-wire circuit
without line compensation
1)
Attention !
Fit short-circuit bridges on the system side on site.
The measured value is applied at logic channel 1. In difference and averaging circuit the
measured value calculation is determined by the measuring type (see above section
”Measuring type coding”). You can get the measured values of the single channels from the
secondary variables.
Measuring type coding
R1, RTD1 or TC1 are used for determining
the secondary variable 1 (Channel 1). R2,
RTD2 or TC2 is used for measuring
secondary variable 2 (Channel 2).
Measuring Measured value
type calculation
Single
channel
Diff 1*)
Diff 2)*)
Average 1*)
Average 2*)
Channel 1
Channel 1 -- Channel 2
Channel 2 -- Channel 1
1
/
2
×
(Channel 1 + Channel 2)
1
/
2
×
(Channel 1 + Channel 2),
in the case of an error as
equivalent value Channel 1 or
Channel 2
1
2 3
4
--
+
1)
TC
1
2
3
4
Pt100
-- +
1)
1
2
3
4
-- +
-- +
1)
TC1
TC2
1
2
3
4
-- +
1)
*) Diff = Difference circuit
Average = Averaging circuit
Figure 5 Sensor pin assignment (continued)