Thirty minute contact time is required to obtain an accurate chlorine residual as prescribed by TB-MED-
577 or by area medical officer.
Perform chloride residual tests on source water as follows (Figure 2-4).
Remove two screws (1) and comparator housing cover (2) from comparator housing (5).
Place chlorine disc (3) on the comparator housing hub (4).
Position comparator housing cover (2) on comparator housing (5) and secure with two screws (1).
Place prism eyepiece (6) over sample cell windows (7).
Select two clean comparator cells (8).
Rinse comparator cells (8) two to three times with source water.
Fill one cell to the 15 mL mark with the source water (obtain water from reservoir fill line).
Figure 2-4. Color Comparator