Water intrusion detection method, water intrusion detection device, and program for device using lubricant

A water intrusion detection device for detecting intrusion of water into a lubricant in a device in which a plurality of portions are lubricated using the lubricant, the device comprising:

• a measurement unit configured to measure an impedance of an electric circuit including the plurality of portions by applying an AC voltage to the electric circuit while sweeping a frequency;
• and
• a detection unit configured to detect the intrusion of water into the lubricant by comparing characteristics indicated by a real part and an imaginary part of an impedance measured in a state in which water is not mixed into the lubricant with characteristics indicated by a real part and an imaginary part of the impedance measured by the measurement unit.

A computer program product comprising a non-transitory computer readable storage medium having instructions encoded thereon that, when executed by a processor, cause the processor to execute a procedure comprising:

• a measurement step of measuring, in a device in which a plurality of portions are lubricated using a lubricant, an impedance of an electric circuit including the plurality of portions by applying an AC voltage to the electric circuit while sweeping a frequency;
• and
• a detection step of detecting the intrusion of water into the lubricant by comparing characteristics indicated by a real part and an imaginary part of an impedance measured in a state in which water is not mixed into the lubricant with characteristics indicated by a real part and an imaginary part of the impedance measured in the measurement step.