Nonelectric initiators

A simple nonelectrical initiating device which can be activated by pressure or by a trip wire. 

The simplest initiators are the nonelectric initiators. They are simple in mechanical construction but not necessarily in terms of their mechanisms of initiation or of their chemical design or performance analysis. The nonelectric initiators can be broken down into four major categories according to the mechanism of initiation flame or spark, friction, stab, and percussion. 

Electric detonators manufactured in North America are equipped with shunts that protect the detonator leg wires from contacting and transmitting stray or extraneous current to the internal detonator mechanism. In areas that are prone to exposure to extraneous current and/or radio frequencies, a blaster may prefer to use detonating cord or other nonelectric initiation system. It is important to understand, however, that even nonelectric sjstems are susceptible to premature detonation caused by lightning strikes, heat, and impact stresses. 

The nonelectric firing system is simple and requires a minimum of equipment. Once initiated, however, it passes from the control of the operator. The electric system can be retained in the control of the operator up to the actual firing. Electric caps also are more waterproof. On the other hand,-the electric system is more complicated, employs more equipment, and may require the operator to remain near the scene at the time of firing. In addition, electric systems can be accidentally activated by static electricity and are hazardous to use in some target situations. 

Now prime the charge with a nonelectric blasting cap and a delay device (time pencil or safety fuse) and initiate the delay. Dual priming is advisable, particularly if the time pencil delay is used. 

The charge may be detonated either electrically or nonelectrically by a blasting cap placed within the explosive/incendiary initiator. Any one of several of the delay systems previously described may be employed. 

Safety fuse A waterproof coated, thread-wrapped cord filled with black powder designed for initiating a nonelectric blasting cap. 

This type of initiator is among the most mechanically sensitive of all the nonelectric types. A typical stab detonator is shown in Figure 23.3. Most stab ini-... 

A relatively recent development in frequency-resolved techniques is the perturbation of an electrochemical system (that is initially in a steady-state condition) by a periodic nonelectrical stimulus. One member in this family of techniques (IMPS, entry 7 in Table 2) has provided a wealth of information on charge transfer across semiconductor-electrolyte interfaces. Reviews are available [2, 9, 10], as is a summary of progress on the use of its electrical predecessor (AC impedance spectroscopy, entry 3 in Table 2) for the study of these interfaces [81]. These accounts should also be consulted for a discussion of the relevant time-scales in dynamic measurements on semiconductor electrolyte interfaces. 

Detonator Any device containing a detonating charge that is used for initiating detonation in an explosive. This term includes, but is not limited to, electric and nonelectric detonators (either instantaneous or delayed) and detonating connectors. 

The explosive charge prepared is inserted into the lead block cavity together with the detonator, and then the cavity is stemmed by dry sand. The sand has a density of 1.35 g/cm and has a particle size below 500 pm. During the testing, the lead block is placed on a 100x100x5 cm st l plate. The explosive charge is initiated by the standard electric or nonelectric detonator. 

The explosive charge is initiated by means of a standard electric or nonelectric detonator. 

For example, fuse detonators may be initiated by safety fuse that is crimped to the detonator (IME recommends that a minimum of 3 ft (0.9 m) of safety fuse be used with each detonator). Safety in the Transportation, Storage, Handling and Use of Explosive Materials 14. Electric detonators are triggered by electric current carried through wires. The power source for nonelectric detonators can be conveyed by detonating cord, detonable gas (infrequently used in North America), and/or shock tube. 

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