8588A/8558A
Operators Manual
Measure Resistance
2-Wire Measurements
For many applications the simple 2-wire arrangement will be adequate. See
Figure 5. However, the value shown includes the resistance of the connecting
leads.
Use a shielded twisted-pair cable, preferably of PTFE insulation, to reduce
induced voltages, induced charge and shunt leakage resistance, particularly
where Rx is high.
2-wire resistance measurement is not available in a Tru Ohms configuration and
is not well suited to use in the 1 Ω range even if the lead resistance is nulled out.
In the latter case, zero compensation for lead and internal resistance
contributions may limit full-scale readout. 2-wire measurements above 1.5 Ω
should be made using higher ranges.
4-Wire Measurements
With a 4-wire connection the lead resistances have negligible effect and only the
value of Rx is displayed. See Figure 6.
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Figure 5. 2-Wire Measurements
Figure 6. 4-Wire Measurements
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