Sensitivity (explosives)
Encyclopedia
Sensitivity of explosives is the degree to which an explosive can be initiated by impact, heat
, or friction
.
Sensitivity, along with stability
and brisance
are three of the most significant properties of explosives that affect their use and application. All explosive compounds have a certain amount of energy required to initiate. If an explosive is too sensitive, it may go off accidentally. A safer explosive is less sensitive and will not explode if accidentally dropped or mishandled. However, such explosives are more difficult to initiate intentionally.
s, such as blasting cap
s. The use of increasingly less sensitive explosive materials to create an escalating chain reaction
is known as an explosive train, initiation sequence, or firing train.
Heat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
, or friction
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...
.
Sensitivity, along with stability
Stability
-Mathematics:*Stability theory, the study of the stability of solutions to differential equations and dynamical systems**Lyapunov stability**Structural stability*Stability of a point in geometric invariant theory....
and brisance
Brisance
Brisance is the shattering capability of an explosive. It is a measure of the rapidity with which an explosive develops its maximum pressure. The term originates from the French verb "briser", which means to break or shatter...
are three of the most significant properties of explosives that affect their use and application. All explosive compounds have a certain amount of energy required to initiate. If an explosive is too sensitive, it may go off accidentally. A safer explosive is less sensitive and will not explode if accidentally dropped or mishandled. However, such explosives are more difficult to initiate intentionally.
Explosive train
Less sensitive explosives can be initiated by smaller quantities of more sensitive explosives, called primers or detonatorDetonator
A detonator is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the latter two being the most common....
s, such as blasting cap
Blasting cap
A blasting cap is a small sensitive primary explosive device generally used to detonate a larger, more powerful and less sensitive secondary explosive such as TNT, dynamite, or plastic explosive....
s. The use of increasingly less sensitive explosive materials to create an escalating chain reaction
Chain reaction
A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions to take place. In a chain reaction, positive feedback leads to a self-amplifying chain of events....
is known as an explosive train, initiation sequence, or firing train.
Classifications
High explosives are conventionally subdivided into two explosives classes, differentiated by sensitivity:- Primary explosives are extremely sensitive to mechanical shockShock (mechanics)A mechanical or physical shock is a sudden acceleration or deceleration caused, for example, by impact, drop, kick, earthquake, or explosion. Shock is a transient physical excitation....
, friction, and heat, to which they will respond by burning rapidly or detonating. - Secondary explosives, also called base explosives, are relatively insensitive to shock, friction, and heat.