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A capacitive distance sensor includes a first guard electrode, a conductor, a second guard electrode, and insulators. The conductor includes a sensor electrode and a lead portion and is arranged on a side of a measurement target with respect to the first guard electrode. The second guard electrode i

A capacitive distance sensor includes a first guard electrode, a conductor, a second guard electrode, and insulators. The conductor includes a sensor electrode and a lead portion and is arranged on a side of a measurement target with respect to the first guard electrode. The second guard electrode is arranged on the side of the measurement target with respect to the conductor. The first guard electrode includes portions overlapping the sensor electrode and the lead portion. The second guard electrode includes a portion overlapping the lead portion and does not overlap the sensor electrode.

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1. A capacitive distance sensor comprising: a first guard electrode;a conductor comprising a sensor electrode, a lead portion extending from said sensor electrode and a terminal portion connected to an end of said lead portion and arranged on a side of a measurement target with respect to said first

1. A capacitive distance sensor comprising: a first guard electrode;a conductor comprising a sensor electrode, a lead portion extending from said sensor electrode and a terminal portion connected to an end of said lead portion and arranged on a side of a measurement target with respect to said first guard electrode;a second guard electrode arranged on the side of the measurement target with respect to said conductor;a first insulator arranged between said first guard electrode and said conductor; anda second insulator arranged between said conductor and said second guard electrode, whereinsaid terminal portion has a first surface at a side of the first guard electrode and a second surface at a side of the second guard electrode as an electric contact for being electrically connected to a signal source,said first guard electrode comprises a portion overlapping said sensor electrode, a portion overlapping said lead portion and a portion overlapping said first surface of said terminal portion,said first guard electrode has one end at a side of said sensor electrode and the other end at a side of said terminal portion,said second guard electrode comprises a portion overlapping said lead portion,said second guard electrode has one end at a side of said sensor electrode and the other end at a side of said terminal portion,said second guard electrode does not overlap said sensor electrode and said second surface of said terminal portion, andsaid terminal portion is positioned between the other end of said first guard electrode and the other end of said second guard electrode. 2. The sensor according to claim 1, further comprising a third guard electrode arranged so as to surround said sensor electrode. 3. The sensor according to claim 2, wherein said third guard electrode includes a portion around said terminal portion. 4. The sensor according to claim 1, further comprising: a third insulator arranged on an opposite side of the measurement target with respect to said first guard electrode; anda fourth insulator arranged on the side of the measurement target with respect to said second guard electrode,wherein each insulator, said first guard electrode, said second guard electrode, and said conductor form a sheet-shaped stacked body in which said third insulator, said first guard electrode, said first insulator, said conductor, said second insulator, said second guard electrode, and said fourth insulator are stacked in an order named,said first insulator has one end at a side of said sensor electrode and the other end at a side of said terminal portion,said second insulator has one end at a side of said sensor electrode and the other end at a side of said terminal portion,said third insulator has one end at a side of said sensor electrode and the other end at a side of said terminal portion,said fourth insulator has one end at a side of said sensor electrode and the other end at a side of said terminal portion,a portion of said first guard electrode is positioned and exposed between the other end of said third insulator and the other end of said first insulator,said terminal portion is positioned and exposed between the other end of said first insulator and the other end of said second insulator, anda portion of said second guard electrode is positioned and exposed between the other end of said second insulator and the other end of said fourth insulator. 5. The sensor according to claim 4, wherein the capacitive distance sensor is adhered to a member arranged facing the measurement target. 6. The sensor according to claim 1, wherein said lead portion has a linear shape narrower than said sensor electrode. 7. The sensor according to claim 6, wherein a width of said lead portion is 0.1 mm. 8. The sensor according to claim 1, wherein said sensor electrode has a circular shape. 9. The sensor according to claim 8, wherein a diameter of said sensor electrode is not less than 0.5 mm and not greater than 1.8 mm. 10. The sensor according to claim 1, wherein at least one of said first guard electrode or said second guard electrode comprises a portion surrounding said sensor electrode. 11. A measurement method of measuring a distance between a first object and a second object, the method comprising: a preparation step of providing a plurality of capacitive distance sensors according to claim 1 on the first object; anda measurement step of inputting a measurement signal to the conductor while maintaining the first guard electrode and the second guard electrode of each capacitive distance sensor equipotential to the conductor,wherein in the preparation step, the plurality of capacitive distance sensors are provided on the first object so that the sensor electrodes of the capacitive distance sensors are arranged at positions different from each other, and each capacitive distance sensor is provided such that the first guard electrode is located on a side of the first object, and the second guard electrode is located on a side of the second object, andwherein in the measurement step, the respective distances between the first object and the second object at the positions are measured by the plurality of capacitive distance sensors. 12. The method according to claim 11, wherein the first object is a bearing,the second object is a shaft,the bearing includes an inner surface directly facing an outer surface of the shaft and an end surface,the sensor electrodes of the plurality of capacitive distance sensors are provided on the inner surface in an axial direction,the terminal portions of the plurality of capacitive distance sensors are provided on the end surface in an circumferential direction, andin the measurement step, distances between the inner surface and the outer surface are measured. 13. The method according to claim 12, wherein the shaft is rotated in the measurement step. 14. The method according to claim 11, wherein the first object is a roller cage, andthe second object is a roller. 15. The method according to claim 14, wherein the plurality of capacitive distance sensors includes distance sensors lead portions of which have lengths different from each other. 16. The method according to claim 11, wherein the first object is a bearing metal,the second object is a crank shaft,the bearing metal includes an inner surface directly facing an outer surface of the crank shaft and an end surface,the sensor electrodes of the plurality of capacitive distance sensors are provided on the inner surface of the bearing metal in an axial direction,the terminal portions of the plurality of capacitive distance sensors are provided on the end surface in a circumferential direction, andin the measurement step, distances between the inner surface and the outer surface are measured. 17. The sensor according to claim 1, wherein said terminal portion has a width wider than a width of said lead portion. 18. The sensor according to claim 1, wherein a range of distances is about 0 to 100 μm.