Millisecond delay detonator

For the manufacture of millisecond delay detonators, faster burning compositions are necessary. Many have been suggested, but the two most commonly used are based on silicon mixed with either red lead or lead dioxide. Typical mixtures would contain between 30 and 50% of silicon and the remainder as oxidising material. 

Millisecond delay detonator. A short delay detonator. 

Fordham (Ref 51, p 127) states that a common mixture for US delay elements consists of Ba peroxide 85 Se 15% and that for the manuf of millisecond delay detonators, faster burning compns are required such as Si 30-50 red lead (or lead dioxide) 50-70%. Manuf of delay compns is described on pp 128-29, assembly on p 129 and design on pp 129 30 of Ref 51. Ger delay compositions (Verzo-gerungsverbindungen) and delay elements(Verzo-gerungskorper) are described In Ref 35, pp Ger 33 Ger 34... 

Gasless delay detonators are manufactured to fire after pre-arranged delay times, each manufacturer providing a series of detonators with intervals of usually 1 s or 0.5 s. More recently a further type of delay detonator has been introduced, usually known as the millisecond, or short delay detonator. Again, manufacturers provide a series of fixed delay times, but in this case the interval between each number of the series is much shorter and may be from 25 to 50 ms. 

PATR 2588 P. Murphy A Graff, Development of a Primer for Use with the T1027E1 Fuze (Jan 1959) (Conf) PATR 2594 D.E. Seeger R.E. Trezona, "Development of the 50-Millisecond-Delay T65 Electric Detonator ... 

Non-electric, short-interval (millisecond) delay devices for use in delaying blasts which are initiated by detonating cord. 

A detonator that has a firing time essentially of zero seconds as compared to delay detonators with firing times of from several milliseconds to several seconds. 

Electric detonators are either of instantaneous or delay action. The electric detonators with delay action have a delay element between the electric fusehead and the initiating mixture. This element provides a half-second, quarter-second or millisecond delay time. 

Other important developments blasting supplies have been a " no-lag electric cap for seismic exploration , "millisecond (MS) delay electric blasting caps , " static resistant (SR) electric caps , "high temperature caps , "special oil-well detonators ,... 

Delay Element. This term may also be applied to a component which provides a specific delay in a blasting cap, detonator, fuze, etc Refs l)0hart (1946), 20 278 2)H.M.Kerr C.R.Hall USP 2560452 (1951) CA 46, 1259 (1952) [Delay elements for electric blasting caps consist of homogeneously mixed powdered metals (such as Mg, Al, Ni, Zn), fuels (such as Si), oxidizers (such as Pb C ) and Misch -metall . By varying the compns, burning times of 15 to 579 milliseconds were obtained] [The Misch-metall (Ger for mixed metal ) is an alloy of rare earths of the following compn ... 

The delayed-action detonators may be set for a delay of half a second (half-second detonators) or for a delay of 2-34 ms (millisecond detonators). Blasting with the latter type of detonators results in a larger yield of blasted stone fragments moreover, a smaller shock will be imparted to the ground around the explosion site. 

Trade name for primer charges with special delay inserts consisting of a sensor on one end and an aluminum shell delay cap on the other. Delay times 0-500 milliseconds in 25 ms intervals. The Deckmaster-unit has to be connected with detonating cord with no more than 30 grains per ft (-< Miniaturized Detonating Cord). For varied delay steps in the hole, only one downline detonating cord is needed. 

Other important developments in blasting supplies have been a no-lag electric cap for seismic exploration , millisecond (MS) delay electric blasting caps , " static resistant (SR) electric caps , high temperature caps , "special oil-well detonators , "waterproof booster for exploding seismograph. sleeper charges in very deep holes , a "millisecond (MS) delay connector for delay firing of Prtmacord", " D eta prime Primers, and electric squibs for military and commercial uses (Ref 6, pp I6 87—99 also Ref 7, pp 6—7)... 

Often another controlled volume of low explosive is placed between the matchhead and the primary charge. This bums for a specified period introducing a delay (from a few milliseconds to a few seconds) into the detonator. However, any low explosive delay device syn. delay electric igniter) introduces imprecision because the chemicals are affected by moisture, temperature, and time. High precision delay electric detonators implant the match-head directly into the primary explosive and control the delay with an integrated circuit within the detonator. 

Delay action below 1 msec and in the lower millisecond range is used in projectiles and bombs that explode on impact on the target but which may do greater damage if a time delay is interposed in order to detonate the missile after penetration of the target. 

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