National Instruments CFP-TC-120, Руководство по эксплуатации, Страница: 6 / 19

FP-TC-120 and cFP-TC-120 6 ni.com
Connecting Thermocouple Input Signals
Connect the positive lead of a thermocouple to the IN(+) terminal
and the negative lead to the IN(–) terminal. If you are using
shielded wiring, connect one end of the shield to the COM
terminal. Thermocouple wires are color coded. The color code
depends on the thermocouple type and the country of manufacture.
If you are unsure which of the thermocouple leads is the positive
and which is the negative, check the thermocouple documentation
or the thermocouple wire spool. The [c]FP-TC-120 supports
thermocouple types J, K, R, S, T, N, E, and B. Figure 5 shows
a shielded thermocouple connected to one channel of the
[c]FP-TC-120.
Figure 5. Connecting a Shielded Thermocouple to the [c]FP-TC-120
The [c]FP-TC-120 linearizes the thermocouple voltage and returns
a reading in units of temperature. The available ranges are
0 to 2,048 K, –270 to 1,770 °C, and –454 to 3,218 °F.
Temperatures outside these ranges result in an
Out of range
error for the affected channels.
Note
You must configure each channel of the
[c]FP-TC-120 for the type of thermocouple connected
to it.
The algorithms in the [c]FP-TC-120 linearize measurements
according to the National Institute of Standards and Technology
NIST-175 standard for thermocouple characteristics, based on the
ITS-90 International Temperature Scale. These linearization
algorithms are typically accurate to within
±
0.05 °C (0.03 °F) of
the NIST standard over the entire range of temperatures defined
by the NIST for the supported thermocouple types.
Thermocouple
[c]FP-TC-120
IN(–)
IN(+)
Shield
C V
To Next
Channel