What is the appropriate method to check the concentration of sanitizer in the third sink?

Using a color chart test strip is the appropriate method to check the concentration of sanitizer in the third sink because it provides a reliable and visual way to assess whether the sanitizer is at the correct strength for effective disinfection. Test strips are designed specifically for this purpose; they react with the sanitizer solution, changing color to reflect its concentration. Comparing the resulting color to a chart allows for accurate measurement, ensuring food safety standards are met.

Other methods do not assess sanitizer concentration effectively. A thermometer measures temperature, which is not relevant to sanitizer concentration. Estimating based on previous uses lacks accuracy and can lead to either over-sanitization or inadequate sanitization, posing a risk to food safety. Rinsing the sink with water does not measure sanitizer concentration and removes the very sanitizer being evaluated, making it ineffective for this purpose.