Patent ID: 9581534
Date: 2017-02-28
CPC Classifications: G01B,G01N

Claim:
1. An apparatus for measuring a wear rate of a test specimen, comprising: a support structure; a test surface supported by the support structure; a test specimen supported by a sample holding fixture on the support structure and engaging the test surface to cause wear of the test specimen; a drive operatively engaging at least one of the test surface and the test specimen to move the other of the test surface and the test specimen relative thereto; a laser displacement measurement apparatus supported by the support structure that reflects a laser off of a surface of one of the sample holding fixture and the test specimen to measure displacement of the test specimen relative to the support structure as a result of the wear of the test specimen, wherein the laser displacement measurement apparatus is a first laser displacement measurement apparatus and a second laser displacement measurement apparatus is supported by the support structure that reflects a second laser off of a wear track formed on the test surface by the test specimen, wherein displacement measured by the first laser displacement measurement apparatus and second laser displacement measurement apparatus are compared to correct for noise factors in displacement measurements, and wherein the second laser displacement apparatus measures the thickness of a film transferred from the test specimen to the test surface, wherein the second laser displacement measurement apparatus measures a first reflection off of the top surface of the film and a second reflection off of the bottom surface of the film to determine a transfer film thickness to correct the measurement of the displacement of the test specimen; and a controller receives data as to the displacement of the test specimen relative to the support structure and data as to operation of the drive over time and is configured to measure the wear rate of the test specimen.