TM 5-4610-233-13&P
b. Solution Feed Adjustment.
NOTE
l Hvpochlorination unit should operate for about 5
minutes before testing.
. Conduct chlorine residual test as prescribed in TM
5-6630-215-12.
(1) Obtain water sample for testing.
(2) Place appropriate chlorine color disk in comparator.
(3) Select two clean comparator cells.
(4) Fill one cell to mark with water sample and insert cell in right-hand cell space of comparator,
(5) Add enough of water sample to cover bottom of second cell.
(6) Add two DPD No. 1 tablets to second cell and crush tablets using plastic rod.
(7) Fill second cell to mark with water sample and insert cell in left-hand cell space of comparator.
(8) Compare water color with color standards of chlorine color disk.
(9) Record result which is closest match as value of free residual chlorine level.
NOTE
If residual chlorine level indication is too low, go to step
11.
(10) Set solution feed pump stroke adjusting knob (6, figure 2-1) to 30 percent and go to step 12.
(11) Set solution feed pump stroke adjusting knob to 70 percent.
(12) Do steps 1 thru 9.
NOTE
If residual chlorine level indication is too low, go to step
14.
(13) Add unchlorinated water to reservoir tank using tank fill valve and go to steps 15.
(14) Adjust solution feed pump stroke adjusting knob to a slightly higher setting.
(15) Do steps 1 thru 9 and continue to adjust solution feed pump stroke adjusting knob until achieving
desired chlorine residual.
c. Refill Reservoir Tank.
(1) Close outlet shutoff cock.
2-8
