Electric detonator types

Lead azide is not readily dead-pressed, ie, pressed to a point where it can no longer be initiated. However, this condition is somewhat dependent on the output of the mixture used to ignite the lead azide and the degree of confinement of the system. Because lead azide is a nonconductor, it may be mixed with flaked graphite to form a conductive mix for use in low energy electric detonators. A number of different types of lead azide have been prepared to improve its handling characteristics and performance and to decrease sensitivity. In addition to the dextrinated lead azide commonly used in the United States, service lead azide, which contains a minimum of 97% lead azide and no protective colloid, is used in the United Kingdom. Other varieties include colloidal lead azide (3—4 pm), poly(vinyl alcohol)-coated lead azide, and British RE) 1333 and RE) 1343 lead azide which is precipitated in the presence of carboxymethyl cellulose (88—92). 

In general, detonation test apparatus consists of a steel tube that is filled with the substance under investigation. One end of the tube is provided with a booster charge consisting of an electric detonator covered by detonative material. The other end is either closed or provided with a witness plate. One type of steel tube apparatus is provided with a velocity probe to record the shock wave velocity as shown in Figure 2.28. 

Electric detonators are also used for detonation of high explosive charges. They are similar in design to other types of detonators except for the presence of an electric fusehead consisting of a bridgewire made of chromium and nickel. The bridgewire is covered by a heat-sensitive pyrotechnic mixture protected by varnish insulation. Standard fuseheads have electrical resistance of 1.2 to 1.4 ohms and... 

Electric blasting caps (or electric blasting initiators) are described in Ref 44, pp B186-R to B186-L. Such caps are called "electric detonators" in Gt Britain. The type known as the "neoprene plug assembly" is described in Ref 36, pp 56-8 and Ref 38, pp 53-6 and is shown here in Fig 7. It consists... 

An other type of British nonmilitary electric detonator, called short type delay detonator" is described in Ref 36, pp 72-3 and is shown here in Fig 11. This detonator con-... 

Fig 13 THEORY OF SERIES FIRING WITH TWO TYPES OF ELECTRIC DETONATORS... 

Fig 1-33 BUTTON-TYPE ELECTRIC DETONATOR T62 Fig 1-34 TYPICAL STAB FUZE PRIMER... 

PATech Paper DB-TP 1-57. R. Goldstein, Mass Production Techniques for Button-Type Electric Detonators T21E1 and T25E1 (Dec 1957)... 

PATR 3064 E.L. Miller, "Development of XM66E2 Electric Detonator for Use in Type 19 Spotting Device" (March 1963)... 

Output tests for detonator type components are generally based on an attempt to measure the brisance or the peak pressure of the shock wave. The common tests for detonators are practically all applicable to each of the three main varieties, namely stab, electric and flash detonators. Following are brief descriptions of output test for detonators and primers ... 

Type 92 Moored Controlled Mine was ellipsoidal in shape, 55 by 41.5 inches, filled with 1100 lbs of Type 88 Explosive. The combined control and mooring cable entered the mine thru the base plate. An electric detonator and booster assembly were bolted to the chge underneath the top cover plate. A microphone to detect the presence of ships was also provided (p 36,... 

In Table E5, p E28 of Vol 5 are given electrical characteristics of US Electric Bridge Type Delay Detonators XM60, T65 and T68 and compns of their spot, primary and secondary (base) charges... 

Eventually a new explosive Hydrobel was developed by Haslam, Davidson and Hancock [94] (Table 154). Submarine-type electrical detonators for short holes... 

Electric Detonators (Industrial). Electric Detonator is the British name for them, but in the USA they are known as " Electric Blasting Caps or M Electric Blasting Initiators described in Vol 2, pp Bl86-rR to B188. Figs of three types are gi en on p B18Bj DuPont s Caps are described in Blasters ... 

Electric Indicators are simulated electric detonators. Two wire bridge types, T-20E1 and T-24E1, are constructed as follows ... 

Electric Primers,Wireless. This class of primers is not equipped with lead wires that are characteristic of other electric detonators but are likewise activated by an electric power source. This type of primer is exemplified by the M—52 A3 series which was standard for the M—99 cartridge or the 20mm ammunition. A typical composition for these primers is as follows ... 

Devel Section Rept No 8 (1957) (Storage stability tests of colloidal LA for use in low energy electric detonators) 19)Purchase Description X-PA-PD-1217(1957) (Tentative spec for Type I and Type II LA s used in the US for military purposes) 20)K.J.Holloway, G.W.C. Taylor A.T. Thomas, ERDE Rept No 7/R/58(l958) (Prepn and props of RD-1343 lead azide) 21)R.L.Wagner, PicArsn... 

Electrically detonated devices may be wired to any switch in the cat they detonate upon turning on the lights, stepping on the brake, releasing the emergency brakes, or some other action. However, this requires an intimate knowledge of the circuitry of the particular vehicle. Below are six types of internal automobile bombs. 

Electric detonators (not fuse and detonators) must be used of not less efficiency than No. 6, the detonation charge of which shall consist of a 1 g mixture of 80 parts of mercury fulminate and 20 parts of potassium chlorate (or their equivalents), and the required electric firing must be done by means of a permissible type blasting unit. 

Igniter Squibs. The squibs are essentially electric detonators except that they produce a flash not an explosion. The commercial type squib, which is also used for military purposes, consists of an aluminum shell 7/8 to l-l/2w long with the flash charge in the bottom of the... 

File or saw through the crimp along line A and remove the nose cap. Some inert M-31 s on the market contain a complete piezo-electric initiator, although the majority do not. If the piezo unit will be used, retain the nose cap and epoxy it back in place AFTER the initiator has been checked and wired into an electric detonator. If a conventional, inertia type initiator is to be used, remove all plastic and rubber parts from the nose. Braze a sheetmetal patch over the hole and reinstall the nose cap with solder or epoxy. 

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