Hydrion QT-40 0-500 PPM Paper Range Quaternary Sanitizer Test Tape Quat Color ChartHydrion QT 40 Quaternary Test Paper provides a simple, reliable, and economical means to measure the concentration of Quaternary Sanitizers, particularly muli quat broad range quaternary ammonium sanitizer solutions. With color matches at 0 150 200 400 500ppm (parts per million), the test paper measures concentrations between 0 500ppm, detecting exhaustion of solutions that should be replaced as well as helping to avoid using excessive amounts of