Abstract
The visual judgement on stains of fibrous products may considerably differ among inspectors because of subjective evaluations. Accordingly, the development of their evaluation methods based on physical measurement is strongly demanded by users. This paper deals with a carpet staining grader designed to enable the determination of absorption factors of stains in the near-infrared range to meet the stain gray scale. The method is based on the fact that the stains of almost all fibrous products absorb the near-infrared radiation, irrespective of their high reflection factor of the products in this range.
