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Return to Terminology
D
- D-Ring
- Shape of the ring pulled by either of the two Gemini
astronauts to eject from spacecraft.
- Dark Igniter
- A priming charge of low luminosity for tracer ammunition.
- Date-Shift Code
- A code applied by manufacturers to the outside shipping
containers, and, in many instances, to the immediate containers of explosive materials to
aid in their identification and tracing.
- Dating
- Dating, in geology, archaeology, paleontology, and physics, is
the determination of the actual or relative age of an object, of a natural phenomenon, or
of a series of events. The most common and accepted method of absolute geologic dating
(establishment of actual age) is based on the natural Radioactivity
of certain minerals found in rocks; because the rate of radioactive decay of any
particular Isotope is known, the age of a specimen can be
computed from the ratio of the remaining isotope and its decay product. Relative
geological dating (determination of the sequence of geological events) is accomplished by
marking out the succession in which rocks were deposited, using various surface criteria.
The identification of fossils in a geological sample is very useful, because certain
assemblages of species are characteristic of specific geologic time periods. Pollen
analysis, or palynology, can also establish the succession of deposits as well as the
climate prevalent at the time of deposition. In archaeology and recent geology, the
carbon-14 method, which measures the remaining amount of this radioactive isotope in
organic matter, can date specimens as old as 35,000 years. The death of an organism
terminates the previous incorporation of this isotope (created by Cosmic-Ray
bombardment) at a rate equal to the isotope's known decay rate. This method's accuracy has
been improved by cross-checking with dendrochronology, in which the age of a piece of
ancient wood can be determined by examining the ring pattern in its cross section. The
pattern of individual ring widths in a sample reflects local climatic conditions occurring
at the time when the piece of wood was a growing tree. By the use of overlapping patterns
found in different wood samples, dating by this method has been carried back over 8,000
years.
Dautriche
Method-Detonation Velocity
- A method of determining detonation velocity of an explosive
material by employing detonating cord and a witness plate.
- DC
- Direct current.
- Dead Pressed
- In an explosive, a highly compressed condition which tends to
prevent the transition from deflagration to detonation that would otherwise take place.
- Deceleration
- The act or process of moving, or if causing to move, with
decreasing speed; the state of so moving.
- Decelerotor
- Device for slowing the rotation of parachute-containing
projectile before ejection of the parachute.
- Decibel
- A unit of air overpressure commonly used to measure air blast.
The faintest audible sound is arbitrarily assigned a value of 0 dB, and the loudest sounds
that the human ear can tolerate are about 120 dB. The difference in decibels between any
two sounds is equal to 10 log10 (P1/P2), where P1 and P2 are the two power levels.
- Decimal Multiples & Submultiples
-
| Multiples and Submultiples |
Prefixes |
Symbols |
| 1018 |
exa |
E |
| 1015 |
peca |
P |
| 1012 |
tera |
T |
| 109 |
giga |
G |
| 106 |
mega |
M |
| 103 |
kilo |
k |
| 102 |
hecto |
H |
| 10 |
deca |
da |
| 10-1 |
deci |
d |
| 10-2 |
centi |
c |
| 10-3 |
milli |
m |
| 10-6 |
micro |
m |
| 10-9 |
nano |
n |
| 10-12 |
pico |
p |
| 10-15 |
femto |
f |
| 10-18 |
atto |
a |
-
- Decomposition
- The process of breaking down a material into more simple
products. Disintegration, dissociation.
- Deflagration
- 1) The chemical decomposition (burning) of a material in which
the reaction front advances into the reacted material at less than sonic velocity.
- 2) Very rapid combustion sometimes accompanied by flame, parks
and/or spattering of burning particles. Deflagration, although classed as an explosion,
generally implies the burning of a substance with self-contained oxygen so that the
reaction zone advances into the unreacted material at less than the velocity of sound in
the material. In this case, heat is transferred from the reacted to the unreacted material
by conduction and convection. Burning rate usually less than 2,000 meters / second.
- Degressive Granulation
- Propellant grain which burns with a continually decreasing
surface until the grain is completely consumed.
- Delay
- A distinct pause of predetermined time between detonation or
initiation impulses, to permit the firing of explosive charges separately. A delay may be
mechanical, pyrotechnic, electronic or an explosive train component that introduces a
controlled time delay in some element of the arming or functioning of a fuze mechanism.
- Delay Detonator
- An electric or nonelectric detonator used to introduce a
predetermined lapse of time between the application of a firing signal and the detonation
of the base charge.
- 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.
- Delay Fuze
- Fuze that has a delay element incorporated in the fuze train
permitting the missile to penetrate the target a distance corresponding to the delay. Such
fuzes are used to permit penetration of the target before detonation or for mining effect.
- Delay Interval
- The nominal time between the detonations of delay detonators
of adjacent periods in a delay series; the nominal time between successive detonations in
a blast.
- Delay Period
- A designation given to a delay detonator to show its relative
or absolute delay time in a given series.
- Delay Series
- A series of delay detonators designed to satisfy specific
blasting requirements. There are basically two types of delay series: millisecond (MS)
with delay intervals on the order of milliseconds, and long period (LP) with delay times
on the order of seconds.
- Delay Tag
- A tag, band, or marker on a delay detonator that denotes the
delay series, delay period, and / or delay time of the detonator.
- Delay Time
- The lapse of time between the application of a firing signal
and the detonation of the base charge of a delay detonator.
- The following chart demonstrates the delay number and its
associated time in milliseconds for particular types of detonators. NOTE: each
manufacturer of delay caps may build their product to slightly different specifications,
therefore a time chart should be acquired for each particular brand of detonator you may
be using. The following is for CXA Delay Detonators.
-
| Delay Number |
Constadet Ò |
Short Delay |
Long Delay |
Delay Number |
Constadet Ò |
Short Delay |
Long Delay |
| 0 |
- |
0 |
157 |
15 |
375 |
725 |
5900 |
| 1 |
25 |
30 |
490 |
16 |
400 |
800 |
6550 |
| 2 |
50 |
50 |
800 |
17 |
425 |
875 |
7250 |
| 3 |
75 |
75 |
1125 |
18 |
450 |
950 |
8050 |
| 4 |
100 |
100 |
1400 |
19 |
475 |
1025 |
|
| 5 |
125 |
128 |
1675 |
20 |
500 |
1125 |
|
| 6 |
150 |
157 |
1950 |
21 |
550 |
1225 |
|
| 7 |
175 |
190 |
2275 |
22 |
600 |
1400 |
|
| 8 |
200 |
230 |
2650 |
23 |
650 |
1675 |
|
| 9 |
225 |
280 |
3050 |
24 |
700 |
1950 |
|
| 10 |
250 |
340 |
3450 |
25 |
- |
2275 |
|
| 11 |
275 |
410 |
3900 |
26 |
800 |
|
|
| 12 |
300 |
490 |
4350 |
28 |
900 |
|
|
| 13 |
325 |
570 |
4850 |
30 |
1000 |
|
|
| 14 |
350 |
650 |
5350 |
|
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- Demolition
- The breaking up of artificial (man-made) structures by
blasting.
- Density
- The density of a substance is its mass per unit volume.
Because many substances, especially gases, can be compressed into a smaller volume by
increasing the pressure on them, the temperature and pressure at which the density is
measured are usually specified. Specific Gravity. The SI
unit of density is the kilogram per cubic meter (kg/m3); the density of
aluminum for instance is 2700 kg/m3. Another common unit of density is the gram
per cubic centimeter (g/cm3). Since 1kg = 1000g and 1m3 = (100 cm)3
= 106 cm3, 1 g/cm3 = 103 kg/m3.
Hence the density of aluminum can also be given as 2.7 g/cm3.
- Water at 3.98° C = 1.000000 grams/ml
- Water at 3.98° C = 0.999973 grams/cm3
- Density Of Charge
- Charge density refers to the mass of an explosive per unit of
volume, usually expressed in grams per cubic centimeter or pounds per cubic foot. Density
is an important characteristic of an explosive. Raising the density (i.e. by pressing or
casting) improves brisance and detonating velocity.
- Design Procedure
- Outline of steps to follow in designing an item. Material
being added.
- Destructor
- An explosive device for intentionally destroying a missile or
aircraft or component thereof.
- Deterrent
- A material applied as a coating on grains of powder to reduce
the initial rate of burning.
- Detonate
- A chemical reaction that progresses through an explosive at a
rate exceeding the speed of sound in the reaction zone.
- Detonating Agent
- Explosive used to set off another explosive. Fulminate of
mercury and tetryl are used as detonating agents to set off other less sensitive
explosives.
- Detonating Charge
- Generally applied to a detonating initiator used to set off a
high-explosive charge.
- Detonating Cord (DC)
- Cord, Detonating. A strong
flexible cord containing a core of detonating explosive, used primarily for initiating a
series of charges. It explodes practically instantaneously throughout its length, when
initiated with a Detonator.
- Detonating Cord Downline
- The section of detonating cord that extends within the
borehole from the ground surface down to the explosive charge.
- Detonating Cord MS Connectors
- Nonelectric, short-interval (millisecond) delay devices for
use in delaying blasts that are initiated by detonating cord.
- Detonating Cord Trunkline
- The line of detonating cord that is used to connect and
initiate other lines of detonating cord.
- Detonating Explosive
- High- Explosive.
- Detonating Primer
- A name applied for transportation purposes to a device
consisting of a detonator and an additional charge of explosives, assembled as a unit.
- Detonating wave
- The shock wave set up when a
detonator is ignited.
- Detonation
- An explosive reaction that moves through an explosive material
at a velocity greater than the speed of sound in the material. A detonation is a chemical
reaction given by an explosive substance in which a shock wave is formed. High temperature
and pressure gradients are generated in the wave front, so that the chemical reaction is
initiated instantaneously. Detonation velocities lie in the approximate range of 1,400 to
9,000 m/s = 5,000 to 30,000 ft/s; slower explosive reactions, which are propagated by
thermal conduction and radiation, are known as deflagration.
- A chemical reaction in which the reaction front advances with
a speed which exceeds the velocity of sound in the material. In this case, energy is
transmitted from the reacted to the unreacted material by a shock wave. Burning rate
usually in excess of 2,000 meters / second.
- Detonation, Low Order
- A chemical reaction in a detonable material in which the
reaction front advances with a velocity which is appreciably lower than that which is the
characteristic detonation velocity for the material in question.
- Detonation Front
- Wave Front.
- Detonation Pressure
- The pressure produced in the reaction zone of a detonating
explosive.
- Detonation Rate
- Velocity at which the detonation wave travels through an
explosive material.
- Detonation Velocity
- The velocity at which a detonation progresses through an
explosive.
- The detonation velocity is the rate of propagation of a
detonation in an explosive; if the density of the explosive is at its maximum value, and
if the explosive is charged into columns which are considerably wider than the critical
diameter, the detonation velocity is a characteristic of each individual explosive and is
not influenced by external factors. It decreases with decreasing density of packing in the
column. It is measured with an electronic decade counter or by the Dautriche
Method.
- Detonation Wave
- The location within an explosive that is undergoing conversion
(reaction) at a particular point in time, and which moves at a velocity known as the
V.O.D. or Velocity Of Detonation. V.O.D. Shock Wave.
- Detonation Zone
- That portion of a detonating explosive in which the chemical
reaction is taking place comprises a chemical reaction zone preceded by a shock wave.
- Detonator
- An explosive train component which can be activated by either
a non-explosive impulse or the action of a primer and is capable of reliably initiating
high order detonation in a subsequent high explosive component of the train. When
activated by a non-explosive impulse, a detonator includes the function of a primer. In
general, detonators are classified in accordance with the method of initiation such as
percussion, stab, electric, friction, flash chemical, etc. A cap or capsule of sensitive
explosive material used to initiate a charge of high explosives. Any device containing any
initiating or primary explosive that is used for initiating detonation. A commercial or
may not contain more than 10 g of total explosives by weight, excluding ignition or delay
charges. The term includes, but is not limited to, electric blasting caps of instantaneous
and delay types, blasting caps for use with safety fuses, detonating cord delay
connectors, and nonelectric instantaneous and delay blasting caps that use detonating
cord, shock tube, or any other replacement for electric legwires. Cap and Blasting Cap.
- DEMEX 100
- DEMEX 400
- Developed Muzzle Velocity
- The actual muzzle velocity produced by any gun.
- DEXS
- Material to be added.
- Diamond
- Diamond is a mineral, one of two crystalline forms of the
element Carbon. It is the hardest substance known, and
inferior stones are used as abrasives, in certain types of cutting tools, and as
phonograph needles. Gem diamonds were first found in streambeds in India and Borneo; most
now come from volcanic pipes in South Africa. Famous diamonds include the Koh-i-noor, now
among the English crown jewels; the Cullinan, from which 105 stones were cut; and the blue
Hope diamond. Synthetic diamonds, produced since 1955, are now widely used in industry,
these are created through the utilization of explosive energy to compress carbon.
- Dichromation
- A chemical treatment given to metals or alloys to inhibit
corrosion.
- Dielectric
- A material that does not readily conduct electricity, i.e., an
insulator ( Insulation). A good dielectric resists
breakdown under high voltages, does not draw appreciable power from the circuit, and has
reasonable physical stability. Dielectrics are used to separate the plates of a Capacitor. The dielectric strength is a measure of the maximum
voltage ( Potential, Electric),
that a dielectric can sustain without significant Conduction.
- Diffraction
- Diffraction is the bending of radiation (such as light) around the edge of an obstacle or by a narrow aperture.
Diffraction results from the Interference of light
waves that pass an opaque body, producing a fuzzy region between the shadow area and the
lighted area that, upon close examination, is actually a series of light and dark lines. A
diffraction grating contains many fine, parallel slits or scratches (about 12,000 per cm
or 30,000 per inch) and disperses light into its colors. These gratings are used in
diffracting spectoscopes. The atomic and molecular structure of crystals is examined by
X-ray diffraction.
- Diluent
- An additive, usually inert, used to regulate burning rate or
temperature.
- Diode
- A two-terminal device having a low Resistance
to electric current in one direction and a high resistance in the reverse direction.
Diodes are thus useful as Rectifiers, converting
alternating current ( AC) into direct current ( DC). Although Electron-tube diodes were once common, almost all diodes today are
Semiconductor devices. In general, current flowing through
a diode is not proportional to the voltage between its terminals. When the voltage applied
in the reverse direction exceeds a certain value, a semiconductor diode breaks down and
conducts heavily in the direction of normally high resistance. This effect can be
exploited to regulate voltage. Some diodes are sensitive to light ( Photovoltaic Cell). A light-emitting diode (LED) produces light
as current passes through it; some LEDs can act as lasers. A thermistor is a special
semiconductor diode whose conductivity increases with the diode temperature.
- Disruptor
- Material to be added.
- Distillation
- Distillation, process used to separate the substances
composing a mixture; it involves a change of state, e.g., liquid to gas, and subsequent
condensation ( States Of Matter). A simple distillation
apparatus consists of three parts: a flask in which the mixture is heated, a condenser in
which the vapor is cooled, and a vessel in which the condensed vapor, called distillate,
is collected. Upon heating, the substances with a higher boiling point remain in the flask
and constitute the residue. When the substance with the lowest boiling point has been
removed, the temperature can be raised and the process repeated with the substance having
the next lowest boiling point. The process of obtaining portions (or fractions) in this
way is called fractional distillation. In destructive distillation various solid
substances, such as wood, coal, and oil shale, are heated out of free contact with air,
and the portions driven off are collected separately. Distillation is used in refining Petroleum and in preparing alcoholic beverages.
- Distribution Series
- The systematic arrangement of data.
- Do’s and Don’ts
- A list of precautions (IME Safety Library Publication No. 4)
printed by the Institute of Makers of Explosives pertaining to the transportation,
storage, handling, and use of explosive materials and inserted in cases of explosive
materials and cartons of detonators.
- Doppler effect
- Doppler effect is the change in the wavelength (and frequency)
of a wave as a result of the motion of either the source or receiver of the waves. If the
source and the receiver are approaching each other, the frequency of the wave will
increase and the wavelength will be shortened - sounds will be higher in pitch and light
will be bluer. If the source and receiver are moving apart, sounds will become
lower-pitched, and light will appear redder ( Red Shift).
Astronomers analyze Doppler shifts of light and radio waves to measure the velocities and
(indirectly) distances of remote objects.
- Double-Based Propellant
- Propellant whose principle active ingredients are
nitrocellulose and nitroglycerin. Propellant.
- Drag
- Component of air resistance in the direction opposite to that
of the motion of the center of gravity of a projectile.
- Drill Ammunition
- Ammunition without an explosive charge, used in training and
practice.
- Driver
- A small unit similar to an explosive switch in which a piston
is pushed forward by a small explosive and / or propellant charge.
- Drogue Gun
- An explosive device designed to eject a slug which is attached
to a drag parachute or similar device.
- Dry Bend
- Combining of fuels and oxidizers by tumbling / spatulating or
rolling by remote equipment.
- Dual Use (Explosive)
- An explosive or more specifically an explosive product which
is utilized for both civil and military applications.
- Dud
- An explosive device that has failed to initiate as intended.
- Dummy Projectile
- Shell that has no explosive charge. Dummy projectiles are used
for practice and training purposes.
- Dwell Time
- In press loading powders into cavities, the interval of time
that the powder is held at the full loading pressure.
- Dynamic Entry
- A description given to the assault element’s rapid and
aggressive movement into and / or throughout the target area.
- Dynamics
- Dynamics is a branch of mechanics that deals with the Motion of objects; it may be further divided into kinematics, the
study of motion without regard to the forces producing it, and kinetics, the study of the Forces that produce or change motion. The principles of dynamics are
used to solve problems involving work and energy, and to explain the pressure and
expansion of gases, the motion of planets, and the behavior of flowing fluids (gases and
liquids). Special branches of dynamics treat the particular effects of forces and motions
in fluids ( Fluid mechanics); these include Aerodynamics, these include the study of gases in motion, and
hydrodynamics, the study of liquids in motion.
- Dynamite
- A high explosive used for blasting, consisting essentially of
a mixture of, but not limited to, nitroglycerin, nitrocellulose, ammonium nitrate, sodium
nitrate, and carbonaceous materials. Invented in 1866 by Alfred B. Nobel, dynamite is
usually pressed in cylindrical forms and wrapped in an appropriate material, e.g., paper
or plastic. The charge is set off with a detonator.
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