Figure 2-4. General layout of detonating cord firing system.
c. Heat and Sun.
(1) Batteries, When the daytime tem-
Extra force is necessary to push the
erature goes above +9°F, use of the mercury
transmitter's fire button at extremely
battery in the receiver will generally give a
cold temperatures. If the rubber boot
longer on-duty time. Mercury batteries gener-
over the FIRE button has been cut,
ally have better high temperature characteris-
moisture can penetrate into the switch
tics than the alkaline types. Because of their
mechanism below and if it freezes,
physical differences (see para 1-11), they may
extremely high force may be necessary
not work properly with some receivers. When
to push the FIRE button.
using a mercury battery ALWAYS check out
the receiver (para 3-9) before the mission (see
Note, para 1-11). Though alkaline batteries
operate well at elevated temperatures, they occa-
b. Moisture. As mentioned above, protect
sionally leak. The leaked material can quickly
both receiver transmitter from moisture.
corrode the contacts which will break the electri-
Both components are moisture resistant and
cal connection between battery and receiver
the internal parts are protected, but the exter-
and turn off the ower (open circuit). When
nal push buttons, switches, and binding posts
this happens, the battery may still be good but
are vulnerable so special care should be taken
it can't get its power to its receiver through the
to protect them, Neither component will oper
corroded contacts. See the maintenance chap-
ate when submerged in water. If they do drop
ter (para 3-4) for corrective action.
into water quickly retrieve them and dry them