Abstract
Reflectance quantitative methods, in visible range of the spectrum, have been studied in our laboratory there is already some time. We have also constructed a very simple portable reflectometer for quantitative analysis that can be used also in spot-test procedures (Matias, Vila e Tubino, 2003; Tubino, Rossi e Magalhães, 1997 ).The first article we published about this subject (Tubino, Ro…