Surface of cell must be kept clean or test results could be inaccurate.
Insert this cell in the right hand cell space (2, Figure 2-5) of the comparator (3).
Collect just enough water to cover the bottom of the second cell (4).
Add two DPD No. 1 tablets to cell (4) and crush with the plastic rod (5).
(10) Fill this cell (4) to the 15 mL mark (6) with the source water and insert it in the left hand cell space (7) of
the comparator (3).
Figure 2-5. Comparator Cells
If the color in the test solution appears between two color standards estimate chlorine content for use in