Patent ID: 7567885

Claim:
An apparatus for measuring a height of an object above a surface of a work piece, the apparatus comprising: a housing including: a first portion having an upper surface and a lower surface; and an extension portion extending a first distance from the lower surface of the first portion, whereby the extension portion defines a cavity opposing the lower surface of the first portion; one or more actuators passing through the lower surface of the first portion of the housing and extending into the cavity; one or more flexible members coupled to the extension portion; a plate having a top surface and a bottom surface, the plate being coupled to the one or more flexible members and disposed in the cavity, wherein the plate is supported by the one or more flexible members to lie in a plane substantially parallel to the surface of the work piece; and a plurality of sensors disposed at predetermined positions of the plate, wherein each of the plurality of sensors is responsive to a height measured between each of the plurality of sensors and the surface of the work piece.