Acceptable Quality Level (AQL) - A nominal value
expressed
as a percentage defective per hundred units, used to identify a
group of sampling plans.
actuator - A mechanical device that transforms
chemical energy into mechanical motion to perform work against an
external load. Types of actuators include bellows, dimple, piston
and retractable.
all-fire - Minimum stimulus which must be applied
to a device for it to reliably function.
ambient - Surrounding meteorological conditions
such as temperature, humidity and pressure.
apparent density - The ratio of mass to volume
of a finely powdered material, under stated conditions, which is
always less than true density. Sometimes called loading density.
arm - To prepare an explosive item for imminent use by
removing safing mechanisms.
average burning rate - The arithmetic mean (statistical
average) of the rate at which a pyrotechnic or propellant will burn
at specific pressures and temperatures.
ballistic pendulum - An instrument used for measuring
the velocity of a projectile or the output of a cartridge or explosive
charge.
binder - Compositions that hold together a charge of finely
divided particles and increase the mechanical strength of plugs
or pellets of these particles when consolidated under pressure.
Binders usually are resins, plastics, asphaltics, or hard waxes
used dry or in solution.
black powder - A low explosive consisting of an
intimate mixture of potassium or sodium nitrate, charcoal, and sulfur.
It is easily ignited and burns consistently at low pressures.
blasting caps - Detonators specifically designed
and produced in high volume far commercial blasting operations.
They come in various sizes (strengths) and can incorporate a delay.
Initiation can be electric or non-electric.
booster - (1) A high-explosive device used to transfer
the detonation from the detonator to the main explosive charge.
(2) An auxiliary propulsion system to aid the early launching phase
of a missile.
bridgewire - A relatively fine resistance wire
incorporated into an ignition element attached to the electrical
leads of an electra-explosive device (EED).
brisance - The shattering ability of explosives.
Bruceton Analysis - A statistical analysis approach
to the problem of determining, as economically as possible, the
behavior characteristics of explosive components by using a limited
number of samples to determine a reliability factor. In this test,
the level of variable applied depends on the results of the previous
test.
bulk density - The mass per unit volume of a bulk
material such as grain, cement, coal. Used in connection with packaging,
storage or transportation.
Bureau of Mines Test - A test for determining the
impact sensitivity of an explosive. A small sample of the explosive
is placed between two hardened steel plates, and a weight is dropped
on the upper plate. The figure representing the lowest height in
centimeters at which at least one of ten trials results in explosion
is the sensitivity index. The highest drop provided is 100 cm, so
sensitivity may be given as 100±, meaning that at 100 cm no explosion
resulted.
burning - A rapid evolution of energy through chemical
reaction between a fuel and an oxidizing agent.
butter charge - An increment of explosive material
that is applied in a paste form and dried in place.
cable cutter - An explosively powered device that
cuts a cable upon the receipt of a firing stimulus.
carbon bridge - A resistive element consisting
of two electrical conductors bridged with a thin spot of colloidal
graphite. Used in initiation systems.
cartridge-actuated device (CAD) - A mechanical
device actuated by a contained or inserted propellant charge.
casting - See melt loading.
closed bomb - A fixed-volume chamber used far testing
the pressure-time characteristics of gas generators, cartridges
or combustible materials.
column length - The length of a propellant or pyrotechnic
composition.
combustion - A continuous, rapid chemical reaction
accompanied by the evolution of energy, commonly caused by the union
of a fuel and an oxidizing agent. (See burning.)
compatibility - Ability of materials to be stored
intimately without chemical reaction occurring. Incompatibility
may result in a loss of effectiveness, or may be hazardous.
composition, pyrotechnic - A physical mixture of
finely powdered fuel and oxidant, with or without additives, to
produce a desired effect.
confidence level - A statistical evaluation of
the percentage of statements or tests expected to be correct using
a given analytical system.
controlled-burning - squib A hot gas/ flame producing
device in which the output charge is designed to burn within the
device.
decomposition - The process of breaking down a
material into more simple products. Disintegration, dissociation.
deflagration - The relatively slow burning or chemical
decomposition of a propellant or pyrotechnic mix such that the reaction
front advances into the unreacted material at less than sonic velocity.
delay - A pyrotechnic or explosive train component
that introduces a controlled time delay in the functioning of a
device or fuze mechanism.
delay element - An explosive train component normally
consisting of a primer, a delay column, and a relay detonator or
transfer charge assembled in that order in a single housing to provide
a controlled time interval.
density of charge - The weight of pyrotechnic or
propellant charge per unit volume of the chamber, usually expressed
in grams per cubic centimeter.
detonate - To be changed by exothermic chemical
reaction, usually from a solid or liquid to a gas, so quickly that
the advancing reaction zone is preceded by a shock wave.
detonation - The extremely rapid chemical decomposition
of a material such that the reaction front advances into the reacted
material at greater than sonic velocity.
detonation velocity - See velocity of detonation.
detonator - An explosive train component which,
when initiated, detonates a less sensitive, but larger high explosive.
Types of detonators include percussion, stab, electric and flash.
drogue gun - An explosive device designed to elect
a weight which is attached to a drag parachute or similar device.
dry blend - A combination of powders that are mixed
in a dry state.
dud - An explosive device that has failed to initiate
as intended.
dwell time - In press-loading powders into cavities,
the interval of time that the powder is held at the full loading
pressure.
EED (electro-explosive device) - Any cartridge,
squib, igniter, etc., which is initiated electrically.
explode - To be changed in chemical or physical
state, usually from a solid or liquid to a gas )as by chemical decomposition
or sudded vaporization), so as to suddenly transform considerable
energy into the kinetic form. See explosion.
exploding bridgewire (EBW)
detonator - A device that achieves detonation by
exploding a bridge element in proximity to, but not in contact with,
a secondary high explosive. Special high-power output-firing sources
must be used to function these devices.
explosion - A chemical reaction or change of state
that is effected in an exceedingly short period of time with the
generation of a high temperature and generally a large quantity
of gas.
explosive A substance or mixture of substances that may
be made to undergo a rapid chemical change, without an outside supply
of oxygen, with the liberation of large quantities of energy generally
accompanied by the evolution of hat gases.
explosive bolt - A bolt that is intended to be
fractured by a contained or inserted explosive charge.
explosive nut - A nut that is intended to be fractured
by a contained or inserted explosive charge For the purpose of releasing
a load.
explosive train - A train of combustible and explosive
elements arranged in order of decreasing sensitivity. The explosive
train accomplishes the controlled augmentation of a small impulse
into one of a suitable energy to actuate a main charge.
flame - A chemical reaction or reaction product,
partly or entirely gaseaus, that yields heat and light.
flash - 1) A burst of heat or flame of short duration.
2) A method of initiating an explosive device using elements that
are sensitive to flame and/or mild shock.
frangible link - A mechanical link that is capable
of supporting a tensile load and releasing the load upon the receipt
of a firing stimulus.
fuel - Any substance used to produce heat by burning.
functioning time - Lapsed time between application
of the firing stimulus to start of pressure rise.
fuse - (Not to be confused with fuze.) An igniting
or explosive device in the form of a cord, consisting of a flexible
fabric tube and a core of low explosive. Used in blasting and demolition
work, and in certain munitions.
fuze A device with explosive or pyrotechnic components
designed to initiate a projectile, bomb, mine, etc.
fuze, delay - Any fuze incorporating a means of
delaying its action. Delay fuzes are classified according to the
length of time of the delay.
gas generator - A device in which a propellant
is burned to produce a sustained flow of pressurized gas.
grain - A single mass of solid propellant in the
final geometric configuration for use in a gas generator or rocket
motor.
hermetic seal - A seal made impervious to air and
fluids. Hermetically sealed devices are generally welded or solder
sealed as opposed to being sealed with epoxy resin, etc.
high explosive - One that detonates.
hygroscopicity - he tendency of a substance to absorb moisture
from its surroundings; specifically, the absorption of water vapor
from the atmosphere.
igniter - A pyrotechnic device used to initiate
burning of a fuel mixture or a propellant.
ignition dropping - A method of loading explosives
in which the explosive is mixed with a liquid vehicle and applied
to the bridgewire. Also called primer spotting.
incendiary - A highly exothermic composition or
material that is primarily used to start fires.
loading density - The quantity of pyrotechnic or
propellant composition per unit volume, usually expressed as grams
per cubic centimeter.
loose charging - Loading an explosive by pouring
it into a container without any pressing.
lot acceptance test (LAT) - See production lot
sampling test.
low explosive - One that burns or deflagrates rapidly,
but does not detonate.
melt loading - Process of loading an explosive
device by melting the explosive and allowing it to solidify in the
device. Also called casting.
primary high explosive - One that detonates if
merely ignited.
priming composition - A physical mixture of materials
that is very sensitive to impact or percussion and, when so exploded,
undergoes very rapid autocombustion.
primer - A primary initiating device to produce
a hot flame. A primary stimulus component generally used to generate
a brisant output for initiating detonating compositions.
primer mixture - An explosive mixture containing
a sensitive explosive and other ingredients, used in a primer.
primer spotting - See ignition dropping.
increment - The amount of pyrotechnic composition
added to the charge, at one time, during the process of loading.
inert - Descriptive of the condition of a device
that contains no explosive, pyrotechnic or chemical agent.
inhibited propellant - A propellant grain in which
a portion of the surface area has been treated to control or prevent
burning.
initiation - The beginning of the deflagration
or detonation of the explosive in an explosive item.
initiator - A device used as the primary stimulus
component in all explosive or pyrotechnic devices such as a detonator,
primer or squib, which, upon receipt of the proper mechanical or
electrical stimulus, produces a burning or detonating action.
input test - A test applied to an explosive device
to determine if it functions upon receiving proper stimulus.
lead - (pronounced "leed") A column of
high explosive used as one component of an explosive train.
linear burning rate - The distance normal to any
burning surface of the pyrotechnic or propellant burned through
in unit time.
no-fire current - Maximum current which can be
applied to a bridgewire circuit without igniting the prime material.
one-amp/one-watt device - An EED which will not
fire or degrade when one ampere and/or one watt is passed through
the bridgewire circuit (usually for a five-minute period).
output test - A test applied to an explosive device
to determine if it does what it is required to do.
oxidizer - A chemical compound which provides the
oxygen for combustion.
pellet - A free-standing, consolidated increment.
percussion - A method of initiating an explosive
device by a sudden sharp blow.
piston actuator - A relatively small actuator
which can receive a stimulus and provide a linear mechanical output
to move, puncture, etc.
power - The rate of doing work.
pressure cartridge - A pyrotechnic device in which
a propellant is used to produce pressurized gas for a short duration.
production lot sampling test (lot acceptance test)
- Test conducted on a sample of a production lot to determine that
the lot meets the specified dimensional and functional characteristics.
progressive burning - The burning of a propellant
grain in which the reacting surface area increases during the combustion.
propellant - An explosive material whose rate of
combustion is low. May be either solid or liquid.
propellant-actuated device (PAD) - A mechanical
device actuated by a contained or inserted propellant charge.
pyrotechnic composition - A mixture of materials
consisting essentially of an oxidizing agent (oxidant) and a fuel.
It is capable of producing a self-sustaining reaction when heated
to its ignition temperature.
qualification test - A series of tests conducted
on an item or system to determine if it meets the requirements established
for the specified use.
recommended firing current - The current which
must be applied to a bridgewire circuit to cause operation of the
device within a specified time.
recommended test current - The maximum current
that can be applied to a bridgewire circuit for an extended period
of time without degrading the prime material.
relay - An explosive train component that, when
initiated, provides the explosive energy needed to reliably initiate
the next element in the train.
reliability - A statistical evaluation of the probability
of a device performing its designed function.
safe - 1) A mechanism that mechanically isolates
the primary explosive from the subsequent elements of an explosive
train. This keeps the item safe for handling until it is ready for
use. 2) To activate a safing mechanism.
safe-arm - A mechanical and/or electrical system
used to arm and safe explosive devices.
secondary high explosive - One that generally must
be detonated by a detonating device.
sensitivity - Susceptibility of an explosive pyrotechnic
component to react to externally applied energy or changes in environment.
spark gap - A method of initiating an explosive
device using high voltage that arcs across an air gap.
squib - Used in a general sense to mean any of
various small size pyrotechnic or explosive devices. Specifically,
a small explosive device similiar in appearance to a detonator,
but loaded with low explosive, so that its output is primarily heat
(flash). Usually electrically initiated and provided to initiate
action of pyrotechnic devices and rocket igniters.
stability test - Accelerated test to determine
the probable suitability of a pyrotechnic or explosive charge for
a long-term storage under a variety of environmental conditions.
stab - A method of initiating an explosive device
that uses a small firing pin and friction-sensitive priming mix.
stability - Ability of explosive or pyrotechnic
materials to withstand long storage under service conditions.
Standard Deviation (sigma) - The square root of
the sum of the squared deviations from the mean. For a given sample
this must be divided by the sample size in order to correct for
bias and be a proper estimate of the true population. A measure
of the variability or dispersion of a number of observations.
stoichiomefric - Relating to components involved
in a burning process which are present in exactly the quantities
needed for reaction, without an excess of any compound.
thermate - An incendiary mixture of various combinations
of thermite and barium nitrate, sulfur and flake aluminum.
thermite - An incendiary or welding composition
consisting of 2.75 parts black iron oxide (ferrosoferric oxide)
and 1.0 part aluminum powder.
velocity of detonation - The rote at which a detonation
front proceeds through a high-explosive charge, generally measured
in thousands of feet or meters per second.
wet blend - A combination of powders mixed with
the aid of a liquid agent which is subsequently evaporated.
|
|
