C-7870 High Range Persulfate Comparator is a component of K-7870 Persulfate CHEMets Visual Test Kit and is designed to be compared against the color formed in R-5510 Peroxide/Persulfate CHEMets Refill. The comparator's range is applicable to many industrial applications. Color standards are orange in color and cover a range of 7 to 70 ppm sodium persulfate.