b. This manual contains preventive maintenance information that
will aid in completing the forms ; pertinent instructions in the manual
are cross referenced to item numbers of the forms in figures 22 and 23.
Projector PH-637(*)/PFP has been lubricated at the factory and,
with one exception, further lubrication of the equipment is not neces-
sary. When the equipment is in daily use, the support post (column)
(fig. 2) which supports the projector head should
be wiped with
oily rag about once a month to remove any grit or dirt which may
have accumulated and to prevent binding of the projection-head tube
on the support post.
Section II. WEATHERPROOFING
Signal Corps equipment, when operated under severe climatic con-
ditions such as prevail in tropical, arctic, and desert regions, requires
special treatment and maintenance. Fungus growth, insects, dust,
corrosion, salt spray, excessive moisture, and extreme temperatures are
harmful to most materials.
41. Tropical Maintenance
A special moistureproofing and fungiproofing treatment has been
devised which, if properly applied, provides a reasonable degree of
protection. This treatment is explained in TB SIG 13 and TB SIG
42. Winter Maintenance
Special precautions necessary to prevent poor performance or total
operational failure of equipment in extremely low temperatures are
explained in TB SIG 66.
43. Desert Maintenance
Special precautions necessary to prevent equipment failure in areas
subject to extremely high temperatures, low humidity, and excessive
sand and dust are explained in TB SIG 75.
The effects of extreme heat or cold on materials and lubricants are
explained in TB SIG 69. Observe all precautions in TB SIG 69
when operating equipment under conditions of extreme heat or cold.