Igniter safety mechanism

Zundpille = squib 296 Ziindschalter = blasting switch 38 Ziindschnur = safety fuse 271, 276 Ziindschraube = fuze head 148 Ziindsicherung = igniter safety mechanism 184 Zundstrom = firing current 141 Ziindung = initiation 191 Ziindverzug = functioning time 77 147... 

The safety barrier analysis principle requires the analysis to start at the potential hazardous energy concentration e.g. rocket motor, igniter, firing mechanism. Causal paths are traced backward from this, moving through the active hardware. Control electronics, C software, sensors operator actions, to the environment in which the C tystems works. At each stage, the safety barriers, which prevent accidents, are noted [6] (see fig. 1). 

Because of the extreme importance of regularity and freedom from failure which must characterise safety fuse, detailed and exhaustive tests must be carried out on the product. Certain controls are obvious, namely, measurement of powder charge and of burning speed, both before and after immersion in water. Other tests usually carried out include resistance to cracking on flexing at low temperatures round a mandrel, coil tests in which the fuse is bunched into flat or complex coils and freedom from failure after immersion in water is determined. New types of fuse are usually tested to indicate the amount of smoke produced and also to determine the adequacy of the end spit. The end spit is the projection of particles of burning powder from a cut end and is of importance because it provides the mechanism which enables the fuse to ignite a detonator. 

Materials for a batch of ammonium perchlorate castable propellant were charged into a mechanical mixer. A metal spatula was left in accidentally, and the contents ignited when the mixer was started, owing to local friction caused by the spatula. A tool-listing safety procedure was instituted [1]. The literature on the kinetics of thermal decomposition has been reviewed critically [2],... 

M51 Electric Detonator is smaller than M48 (0.194-inch in diam by 0.37- inch long), but the reduction of space available for expl chge is partially offset by replacement of the pressed ignition chge with a spot of colloidal LA mixed with NC lacquer. This detonator has been used in safety and arming mechanism of Nike Ajax, which is an Army surface-to-air guided missile designed to seek and destroy enemy planes... 

During the mechanical loading of the fuse core, small sections more than 2mm long are sometimes not filled with BlkPdr due to malfunction of mechanical parts. These faults are only observed when they interrupt the propagation of the flame when the fuse is ignited. These undetected faults can cause safety problems to workers in the field and also considerable loss of time... 

Ring, M. A. et al., AIP Conf. Proc., 1988, 166 (Photovolt. Safety), 175—182 Very pure silane does not immediately explode with oxygen, but the decomposition products may ignite after a delay [1]. Mixtures of silane with 30% oxygen are metastable and potentially explosive under all pressure conditions studied, and become explosive at above 80°C. Addition of a few % of disilane renders the mixtures much more explosive, and mechanisms are proposed [2],... 

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