Specifications

Terminal Connector Method:

In order to make short repeatability small, there are test fixtures which utilize the 4-Terminal con-

nector method (for example 16044A). By employing this technique, the effect of contact resistance is

reduced and short repeatability is drastically improved. As a result, the range of accurate low imped-

ance measurements is vastly expanded.

In the figure below, the difference between the 2-Terminal connector and the 4-Terminal connector is

shown. In a 2-Terminal connector, the contact resistance, which exists between the fixture’s contact

and the DUT, is measured together with the DUT’s impedance. Contact resistance cannot be elimi-

nated by compensation because the value changes each time the DUT is contacted.

2-Terminal and 4-Terminal connector techniques

In a 4-Terminal connector, the voltage and current terminals are separate. Since the input imped-

ance of the voltmeter is large, no current flows to the voltage terminals. Hence, the voltage that is

applied across the DUT can be accurately detected without being affected by the contact resistance.

Also, the current that flows through the DUT flows directly into the current terminal and is accurate-

ly detected without being affected by the contact resistance. Due to the reasons stated above, it is

possible to eliminate the effect of contact resistance and realize a small short repeatability.

Appendix Additional Error