Instantaneous fuse

Moment-aufnahme, /. instantaneous exposure or photograph, -bild, n. instantaneous photograph, snapshot, -klemme, /. instantaneous clamp, -ziinder, m. instantaneous fuse, detonator, -ziindpille, /. flash pellet primer, -zundung, /. instantaneous ignition or firing. 

For some purposes, particularly in fireworks, instantaneous or almost instantaneous transmission of flame is required without detonation such as is characteristic of detonating fuse. Instantaneous fuse is used for this purpose, deliberate use being made of one of the possible faults in safety fuse, namely, the rapid speeding up which can occur if the core of the safety fuse is porous. 

Instantaneous fuse. A fuse which propagates by burning at high velocity. 

Instantaneous Fuse. This fuse, burning at the rate of 100 to 300 feet per second, was formerly much used in blasting operations where a number of charges had to be fired simultaneously. It has now been replaced by detonating fuses and electric detonators... 

Instantaneous fuse was made by wrapping several strands of quick match in waterproof tape. The fuse was fired by means of a percussion cap in a special pistol... 

In OrdnSergeant (Ref 4a, p 18) is described a WWII Instantaneous Fuse for Initiation of Demolition Charges which contd a core of MF 79.4 with wax 20.6%. When initiated by a cap, the fuse functioned at the rate of about 20000ft/s (6100m/s). If initiated by flame it will burn but its use as slow burning fuse was not recommended... 

In the case of large cast-iron objects, preference is given to application of dry powdered frit onto a pre-heated product by means of vibration sieves. The powdered enamel is instantaneously fused onto the hot surface. Small objects are enamelled by dipping the hot object in powdered frit. 

Primacord, or detonating cord, differs from time fuse in that it detonates practically instantaneously along its entire length rather than burning progressively and relatively slowly. 

Depending upon the purpose and circumstances of the job to be done, the operator will need different ways of setting off his charges. He may need only a short delay, such as may be provided by a piece of time fuse, to permit him to get out of range of the explosion. He may need a reasonably accurate delay of several hours. He may wish to initiate the action instantaneously himself at a precise moment. Or he may wish to have the action initiated by the target. 

Fig. 17 — Chemical Instantaneous Initiator open end of the fuse lighter.

The technique of H NMR thermal analysis (25) yields data In the form of M2J pyrograms (typical examples are shown In Figures 1 and 2). The fusibility of a coal can be ranked by the minimum value of M2J (M2jmln) attained during the experiment. This parameter measures the Instantaneous maximum extent of fusion of the sample on a molecular level and not the total fraction of material that passes through a fused state during heating. 

Whilst quickmatch can be used to form simple fuses for fireworks, both internally and externally, a burning time of some 40 sm is too long in instances when a more or less instantaneous ignition is required. Also, quickmatch is rather fragile and tends to kink or lose powder unless it is coated in some way. 

Quickmatch. Fast burning fuse made by impregnating cotton wick with mealed (finely powdered) or unmealed BkPdr. Gum arabic or dextrin is used as a binder. Quickmatch is highly sensitive to moisture and must be kept dry for proper functioning. It burns almost instantaneously when confined (Ref 23, pp 2-21 to 2-22 USSpec JAN-Q-378)... 

Demolition Fuse, Instantaneous is described under Fuse (Miccia)... 

Methylpyridinium ions (181) react reversibly with hydroxide to form a small proportion of the pseudo-base (182). The term pseudo is used to designate bases that react with acids measurably slowly, not instantaneously as for normal acid-base reactions. Fused benzene rings reduce the loss of resonance energy when the hetero ring loses its aromaticity and hence pseudo-bases are formed somewhat more readily by 1-methylquinolinium, 2-methylisoquinolinium and 10-methylphenan-thridinium, and much more readily by 10-methylacridinium ions. Pseudo-bases carrying the hydroxy group in the a-position are usually formed preferentially, but acridinium ions react at the y-position. 

---