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-1306External Sensor
ON
I = 100 µA
+
EX1+
AI1+
AI1–
EX1–
I = 100 µA
ON
R
L3
R
L1
R
L2
R
T