removable, plastic color disks. One disk is for measuring chlorine residual and is
graduated in values of 0.1, 0.4, 0.7, 1.0, 1.5, 2.0, 3.0, 5.0, and 10.0 ppm. The other disk
is a wide range pH disk, graduated in even pH values from 3.0 to 11.0. The comparator
is equipped with two glass tubes: the one right (outside) is referred to as the blank,
which reflects the natural color of the water; the one on the left (inside) is referred to as
the indicator. The difference in color between the blank and the indicator is compared,
by means of a prism inside the comparator, to a like color on the appropriate color disk.
When the colors match, the reading is made directly from the disk.
Figure 4-2. Color comparator with case.
(2) Water Quality Analysis or Control Sets. These are referred to in this
subcourse as Water Quality Analysis or Control Sets Water Quality Analysis or Control
Sets (WQAS or WQCS).
(a) General. The WQAS are authorized under current TOE for the
division medical battalion, medical companies medical support battalion, medical teams
LB (environmental sanitation) and LC (environmental engineering service), and all
engineer units equipped with water purification equipment. The sets are designed for
use as field sampling and testing equipment by personnel with a minimum of chemical
training. The WQAS are entirely contained in a fiberglass case 16 inches high, 22
inches wide and 22 inches deep. The interior of the cases is Iined with foamed plastic
inserts to protect the equipment and supplies and to keep them in an upright position.
The WQAS are proportioned in order to weigh less than 65 pounds each and to be