Patent ID: 11674990

Abstract:
To easily measure a voltage to ground of electromagnetic interference waves generated on a cable. A capacitance-to-ground measurement mechanism 10 includes a first electrode 11 and a second electrode 12 positioned at equal altitudes to be opposed to the earth, and a first voltage measurement device 15 to measure a voltage generated in a first resistance 14 connected between the first electrode 11 and the second electrode 12 by an output signal from an oscillation circuit 13. A voltage-to-ground measurement mechanism 30 includes a GND electrode 31 positioned at an altitude equal to that of the first electrode 11 and the second electrode 12 to be opposed to the earth, and a second voltage measurement device 33 to measure a voltage generated in a second resistance 32 connected between the GND electrode 31 and a probe 34 that is brought into contact with a cable core 106 as a measurement target. A computation mechanism 50 includes a computation device 51 to calculate a voltage to ground of electromagnetic interference waves generated on a cable based on data of respective voltages measured by the capacitance-to-ground measurement mechanism 10 and the voltage-to-ground measurement mechanism 30.