The C-8510 Flat Phosphate Comparator is a component of K-8510 and K-8520D poshpate test kits. It is designed to be compared against the color formed in R-8510 Phosphate, ortho CHEMets® Refill. The comparatorandapos;s range is applicable for many industrial water, wastewater, and environmental water quality applications. The color standards contain blue dye mixtures that are formulated to match the colors produced by the test ampoules. Range: 1 to 10.0, 10 to 100 ppm.