Detects exhaustion of solutions that should be replaced as well as helps to avoid using excessive amounts of sanitizing agents. Measures concentration of n-alkyldimethylbenzyl and/or n-alkyl dimethyl ethyl benzyl ammonium chloride, and Rocall II. Federal, State, and Local health regulations require users of Quaternary Ammonium Sanitizer Solutions to have appropriate test kits available to verify the strength of sanitizer solutions.