National Instruments Module SCXI-1503 - Manual (Page 19)

Chapter 2 Connecting Signals
SCXI-1503 User Manual 2-6 ni.com
Lead-Resistance Compensation Using a 3-Wire Resistive Sensor and
Two Matched Current Sources
You can compensate for the errors introduced by lead-resistance voltage
drops by using a 3-wire resistive sensor and two matched current sources
connected as shown in Figure 2-4.
Figure 2-4. 3-Wire Configuration Using Matched Current Sources
+
–
SCXI-1503
EX0+
AI0+
AI0–
EX0–
SCXI-1306 External Sensor
ON
I = 100 µA
+
–
EX1+
AI1+
AI1–
EX1–
I = 100 µA
ON
R
L3
R
L1
R
L2
R
T