The FPC four-wire high breakover voltage testing machine 9331 is the ideal solution for breakover impedance of few points and high voltage insulation. This is especially the case with flexible circuit board FPCs vulnerable to expanding, contracting, and bending. FPCs tend to suffer defects of varying copper wire widths, notches, and burrs due to different materials and etching time, and chemical solutions when going through the process. Aiming at short-circuit or open circuit, precision resistance of copper wires and capacitance impedance between wires, the 9331 goes live for testing by just connecting to a manual/pneumatic compact press thimble jig. It not only enables board makers to run 4-wire precision measurement with speed and accuracy, but also cuts PCB O/S test machine investment with less workshop space demand.