National Instruments 1128, SCXI-1127 user manual -

Chapter 2 Using the SCXI-1127/1128
SCXI-1127/1128 User Manual 2-18 ni.com
Figure 2-16. Temperature Measurement Wiring Diagram
The SCXI-1331 contains a cold-junction temperature sensor (CJS). This
sensor is a special channel on the SCXI-1127/1128 dedicated to measuring
the ambient temperature of the terminal block. This channel is always
scanned as a 2-wire channel. Including a CJS channel in the scan list is
optional. You can include a CJS channel at any position in the list with any
number of repetitions.
The SCXI-1331 temperature sensor outputs 0.2–0.024 V from 0–50 °C and
has an accuracy of ±0.5 °C over the 15–35 °C range and ±0.9 °C over the
0–15 °C and 35–50 °C ranges.1
National Instruments software can convert a thermistor voltage to the
thermistor temperature. In LabVIEW, you can use the Convert Thermistor
Reading virtual instrument (VI) in the Data Acquisition»
Signal Conditioning palette. If you are using Measurement Studio or
1 Includes the combined effects of the temperature sensor accuracy and the temperature difference between the temperature
sensor and any screw terminal. The temperature sensor accuracy includes tolerances in all component values, the effects
caused by temperature and loading, and self-heating.
SCXI-1127/1128
R1
-
+
Iex
RTD
Thermistor R2
V1
Thermocouple