100 Noble QT Test Strips Ensure your solutions are safe for use with these Noble Chemical QT-10 quaternary test strips! Noble Chemical QT-10 quaternary test strips are the simple, reliable, and economical way to measure the concentration of quaternary sanitizers, including n-alkyldimethylbenzyl and/or n-alkyl dimethyl ethyl benzyl ammonium chloride, and rocall II. Each strip measures concentrations between 0-400ppm (parts per million), with color matches at 0, 100, 200, 300, and 400ppm.