IMPEDANCE MEASURING METHOD BY FOUR-TERMINAL METHOD

摘要

PROBLEM TO BE SOLVED: To prevent an induced voltage which causes a measurement error from being generated on a voltage probe side by a magnetic field produced at a current probe. SOLUTION: For an impedance measuring method by a four-terminal method using 1st and 2nd voltage probes 11 and 12 and 1st and 2nd current probes 21 and 22, a conductive substrate 3 is arranged on the reverse side of a circuit board (measured body) 3 and 3rd and 4th current probes 23 and 24 are arranged along the 1st and 2nd current probes 21 and 22 and then made to probe the conductive substrate 3, thereby supplying a cancel current CI by a measurement current I in such a direction that magnetic fields produced at the 1st and 2nd current probes 21 and 22 are canceled.