Patent · US Expired

Capacitive sensor for non-contacting gap and dielectric medium measurement

US7084643B2 · kind B2 · utility

39Cited by
3References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 25, 2006
Grant dateAug 1, 2006
Priority date
Expiry dateJan 25, 2026

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01B7/14
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A non-contact capacitive sensor including: a sensor plate configured to be displaced from a surface and to measure a capacitance of a gap between the surface and sensor plate; an active shield plate over the sensor plate and insulated from said sensor plate, wherein a high frequency input signal is applied to the active shield plate and sensor plate; an effective ground shield plate connected through a first resistor to a ground, over the active shield plate to sandwich the active shield plate between the ground shield plate and the sensor plate, and the ground shield plate is insulated from the active shield plate, and a second resistor connected between the ground shield plate and the active shield plate to provide a direct current (dc) path through the sensor.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.