2- and 4-Terminal Method

A normal multimeter, equipped with 2 terminals, is a cheap and simple instrument for measuring voltage, current and resistance. However, the conventional 2-terminal method is not suitable for material evaluation.


 

The 4-terminal probe of the Loresta GX eliminates lead-wire connector and contact resistance. More precise measuring of resistance is  achieved.

Vierleiterverfahren

 

In the case of the 4-pin probe method, 4 needle-type electrodes are placed linearly on a sample. A certain current flows between 2 external pin probes (1 and 4), and a potential difference formed between 2 inner pin probes (2 and 3) is measured to determine the resistance.

Elektrodenanordnung der Vier-Punkt-Messmethode(

 

Then, multiplying the measured resistance (R in the unit of Q) with the sample thickness (t) and the Resistivity Correction Factor (RCF) derives the volume resistivity. In this way, the 4-pin probe method and 4-terminal method have a common measurement system, but the electrode sections in contact with the sample is different.

Only the placement of a probe on a sample is required for measurement in this 4-pin probe method, but electrode formation over the sample is not required unlike the 4-terminal method and thus the procedure is remarkably more efficient.

ASP Messkopf Vierpunktmessung
ASP Messkopf Vierpunktmessung