Detonator
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A detonator, or blasting cap, is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the latter two being the most common due to their simplicity.
Contents
General
Detonators consist of a small tube filled with a primary explosive, such as ASA (lead azide, lead styphnate and aluminium), DDNP (diazo dinitro phenol), mercury(II) fulminate (sometimes mixed with potassium chlorate/perchlorate), tetryl, etc. and a fuse. Other explosive materials, such as organic peroxides (TATP, MEKP, HMTD) can be used, though their use is discouraged as these materials are too sensitive to be handled safely.
Types
Ordinary detonators
Ordinary detonators are ignition-based explosives. This form of detonator is most commonly initiated using safety fuse, and used in non time-critical detonations. Well known detonators are mercury(II) fulminate, lead and silver azide.
Electrical detonators
There are three categories of electrical detonators: instantaneous electrical detonators (IED), short period delay detonators (SPD) and long period delay detonators (LPD). SPDs are measured in milliseconds and LPDs are measured in seconds.
Non-electric detonators
A non-electric detonator is a shock tube detonator designed to initiate explosions, generally for the purpose of demolition of buildings and for use in the blasting of rock in mines and quarries. Instead of electric wires, a hollow plastic tube delivers the firing impulse to the detonator, making it immune to most of the hazards associated with stray electric current. It consists of a small diameter, three-layer plastic tube coated on the innermost wall with a reactive explosive compound, which, when ignited, propagates a low energy signal, similar to a dust explosion.
Electronic detonators
Electronic detonators are designed to provide the precise control necessary to produce accurate and consistent blasting results in a variety of blasting applications in the mining, quarrying, and construction industries. Electronic detonators may be programmed in 1-millisecond increments from 1 millisecond to 10,000 milliseconds using the dedicated programming device called the logger.
Availability
Detonators can be purchased from companies that deal with commercial explosives. A permit is required for them.
DIY detonator
Handling
Safety
Detonators should be inspected for any defects. Make sure the material they're made of is compatible with the primary.
Legality
The manufacturing and possession of detonators without permit is a crime in most countries.
Storage
Detonators should be used as soon as possible. If you want to store them for later use, keep them in a resistant box in a safe place.
