TM 09241 B-12&P
2-12. OPERATION OF COLOR COMPARATOR. - continued
Hold the comparator housing (2) up and look through the eyepiece (3). Face a good light source (daylight, but
not the direct rays of the sun, or artificial light reflected from a white surface). Be sure your fingers do not cover the light
window in the back of the comparator housing. Rotate the color disc (4) until a color on the disc matches the color of the
comparator cell (7) in the left opening. The reading can be made directly from the window (5) in the front of the comparator
housing. If color falls between readings, estimate.
Remove comparator cells (6) and (7) from comparator housing (2) and discard water samples and solutions.
Thoroughly rinse all equipment with demineralized or distilled water.
(2) Perform chlorine residual test.
Remove color disk (10) (Chlorine) and insert into housing (2). Numbers must be visible through indicator
Figure 2-14. pH/Chlorine Test