Estimating the resistance of wires in your DUT - an online calculator

Use this calculator when you want to choose thresholds for your wire tests. This calculator will estimate the resistances of your fixturing, the connector's contact resistance, the device under test (DUT) resistance, and variations caused by temperature and measurement accuracy. If you have any questions about cable or harness testing call us toll-free 1-800-441-9910.

Step 1) Find the Wire Resistances

Units of Measure

 All lengths in
All resistance values in ohms
All wire gauges are AWG
All wire is copper		 Diagram of calc model

Your Fixturing

 The wire from tester to:
Point A: Length Gauge ___ ohms
Point B: Length Gauge ___ ohms
Contact resistance from fixture to DUT:
At Point A: ohms ___ ohms
At Point B: ohms ___ ohms

Your Device Under Test

 Wire in DUT:
Length Gauge ___ ohms

Wire Resistance Results
Expected resistance of:
A 2-wire measurement: ___ ohms
A 4-wire measurement (points combine at A and B): ___ ohms
4-wire measurement (points combine on DUT): ___ ohms
Step 2) Factor in the Variations

Variations

 Wire Resistance %
Wire Length %
Max Temperature ° ___%
°F or °C
Accuracy of Tester
Percent of reading %
Fixed error ohms

Recommended Thresholds
Highest Expected Resistance for 2-wire: ___ ohms
Highest Expected Resistance for 4-wire (points combine at A and B): ___ ohms
Highest Expected Resistance for true 4-wire (points combine on DUT): ___ ohms