The probe guidance system is kinematic and thus free of all lateral play. The needles are positioned by upper and lower jeweled guides, each needle being constrained by a spring-loaded ruby ball at each guide.
Four-Point-Probes offers 4 point probe equipment for measuring the sheet resistance and bulk (volume) resistivity of materials used in the semiconductor industry, universities, and in materials science including thin films, wafers, ingots, and other materials and conductive coatings.