Patent ID: 8975586
Filing Date: 2015-03-10
Classification: G01B,G01J,G01N,G02B

Abstract:
1. An apparatus for sensing a layer of material that comprises: a radiation source, disposed on one side of the layer of material, that directs a beam of incident near and mid infrared radiation having wavelengths of more than 5 microns into the layer of material; a radiation receiver that detects at least a portion of a reflected beam that propagates through the layer of material; and one or more members that define a measurement cell with a path for the layer of material, wherein each member includes a diffuser comprising a layer of alumina, which is translucent to the near and mid infrared radiation from the radiation source, and that is formed on a specular reflective surface, wherein the layer of alumina has a smooth side that faces and is adjacent to a side of the layer of material and wherein the measurement cell is configured to cause radiation to be reflected through the layer of material a plurality of times before being detected by the radiation receiver and wherein the diffuser does not include quartz or plastic.