Patent ID: 8730482
Filing Date: 2014-05-20
Classification: G01B

Abstract:
1. A method for measuring a wear rate of a consumable member having a wear surface exposed to an environment causing the consumable member to wear out and a non-wear surface parallel to the wear surface and exposed to an environment without causing the consumable member to wear out, the method comprising: inserting a non-consumable member into a recess formed in the consumable member, the non-consumable member being a different member from the consumable member; thermally coupling the non-consumable member with the consumable member, the non-consumable member being made of the same material as the consumable member and having a first non-wear surface and a second non-wear surface, both the first and second non-wear surfaces being parallel to each other and exposed to an environment without causing the non-consumable member to wear out; irradiating a low-coherence light beam to the consumable member orthogonally to the wear surface and the non-wear surface, receiving reflection light beams of the low-coherence light beam from the wear surface and the non-wear surface and measuring a first optical path length of the low-coherence light beam that travels forward and backward within the consumable member in a thickness direction thereof; irradiating a low-coherence light beam to the non-consumable member orthogonally to the first non-wear surface and the second non-wear surface, receiving reflection light beams of the low-coherence light beam from the first non-wear surface and the second non-wear surface and measuring a second optical path length of the low-coherence light beam that travels forward and backward within the non-consumable member in a thickness direction thereof; and calculating a wear rate of the consumable member based on a ratio between the first optical path length and the second optical path length.