TM 5-4610-223-12
c.
Hunter Heater, Stopping.
(1)
Place heater toggle switch (8, fig. 2-29) in OFF position.
(2)
Close fuel shutoff valve (7).
NOTE
The heater will continue to operate and the indicator light will continue to glow until the heater has
purged itself of fuel.
(3)
If the heater is to be shut down for a long period of time, disconnect the electrical cable plug connector
from the power receptacle connector.
d.
Hunter Heater, Ventilation.
(1)
In warm weather or when it is desired, unheated fresh air can be drawn in through the grill connected to the
fresh air source (fig. 2-29).
(2)
Open the louver by moving handle (3) downward.
(3)
Place toggle switch (8) in FAN ON position. This closes a circuit to the air circulating blower motors and
another to the indicator light (5), and both will operate.
2-9. CHLORINE RESIDUAL TEST COMPARATOR (NSN 6630-01-044-0334).
a.
Test Precautions. As with all chemicals, caution must be exercised in handling orthotolidine and sodium
arsenite. Never pipette by mouth and wash hands carefully after each use. To insure greatest accuracy, several other
precautions should be followed:
(1)
Color discs and indicator solutions. Color disc and solutions are adjusted for sample tubes for having a 26
mm depth and on the basis of 15 cc of water sample and 0.75 cc of indicator solution. The graduated mark on the
sample tubes is at 15 cc. The graduated mark on the dropper is at 0.75 cc. The disc supplied with the comparator
measures 0.1 to 10.0 ppm chlorine residual.
(2)
Cleanliness.
(a)
Before taking readings be sure that the glass color standards in the disc are clean.
(b)
When taking samples, adding solutions, and mixing solutions with water in the sample tubes, be sure
that the hands are free of all traces of chemical so that the sample will not be contaminated. Any contamination of the
samples will produce erroneous readings.
(c)
Care must be taken not to contaminate the indicator solution by the introduction of droppers that are
not perfectly
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