SPIE Proceedings [SPIE IV Iberoamerican Meeting of Optics and the VII Latin American Meeting of Optics, Lasers and Their Applications - Tandil, Argentina (Monday 3 September 2001)] 4th Iberoamerican Meeting on Optics and 7th Latin American Meeting on Optics, Lasers, and Their Applications - Determination of the sensitivity coefficient related to gloss estimation as a function of the temperature in the evaluation of its typical uncertainty