PH Pencil From SDL America
SDL America Inc., Charlotte, N.C., has introduced a pH pencil, for quick and easy determination of
surface pH on wet or dry goods, yarns, or solutions, if a few drops are placed on a filter paper. A
pencil mark on the substrate will change color according to the pH of the material. The mark can
then be compared to a color chart, on which each color corresponds to a certain pH.