Figure 101. Teat setup for initiators.
controlled pressure of the Krypton gas causes
recorded so that, in the event of malfunction or
radioactive gas to flow through any leakage paths.
failure, the units may be checked against their
Cartridges that have leaked contain radioactive gas and
original dimensions. All cartridges should be X-
emit small amounts of gamma radiation. The radiation
rayed to ascertain proper assembly of primer
is measured, which indicates the amount of material that
components.
has leaked into the cartridge. This process detects leak
(3) The firings which must be conducted and the
rates so small it would take an undetected leak
characteristics which must be recorded are
thousands of years to leak one cubic inch of air into an
determined by the design requirements. The
evacuated chamber.
following ballistic firing program is typical,
This test also may be used to test small propellant
except when a device contains a component or
actuated devices for leaks.
subassembly that is identical to one that is a
part of an already standardized device; then all
95. Development Evaluation Program. a. General.
or a portion of the ballistic firings may be waived
(1) During the development program, newly
by agreement with user.
designed propellant actuated devices are
b. Workhorse Model Evaluation.
evaluated to insure that they meet design
(1 Workhorse models are used to develop the
requirements.
Workhorse models, strong
charge, determine the locked-shut pressure, and
enough to stand repeated firings, are fabricated
check the general operation. The workhorse
from design drawings. These workhorse models
model may include provisions for measuring
are fired to develop the proper charge and to
characteristics which may not be measured in
assure the feasibility of the design. After charge
later models; for example, it may be designed to
development and the elimination of weaknesses
accept pressure pickups or piezoelectric gages
in design through firings and modification of the
to record internal pressure.
workhorse models, several prototype models
(2) Normally, the following test program is utilized.
are fabricated and evaluated.
Workhorse models are fired at 70 F. to
(2) Prior to development firings, it is important that
establish the propellant charge. A minimum of
all devices be given a 100 percent inspection
three rounds are fired
and the dimensions
110
