General Requirements

• Put the color disc on the center pin in the color comparator box (numbers to the front).

• Use sunlight or a lamp as a light source to find the color match with the color comparator box. Natural light works best.

• If the color match is between two segments, use the value that is in the middle of the two segments.

• If the color disc becomes wet internally, pull apart the flat plastic sides to open the color disc. Remove the thin inner disc. Dry all parts with a soft cloth. Assemble when fully dry.

• Undissolved reagent does not have an effect on test accuracy.

Testing Requirements

• From a sink that you use often, run cold water until you feel a change in the temperature. It can take up to five minutes and will get noticeably cooler. This ensures that you are testing water from the main line and not the water in your house.

• Rinse the tubes with a water sample before the test.

• Read the result immediately after the reagent is added to prevent interference from monochloramine.

• If the test is out of the optimal range, please report your findings immediately by calling Customer Service at 866-357-8783.

• Record the results on the Daily Customer Chlorination Report Form.

• Email your completed report to PUDCustomerService@ThurstonPUD.org by the 5th of the following month.