Sensitivity flame

Sensitiveness to Flame. See under Ignition and Explosion of MeN by Flame Sensitiveness to Initiation. MeN is more sensitive, than NG. For example, when it is initiated with a No 1 cap, under w tamping, the detonation effectiveness is equal to 88% of that with a No 8 cap, while NG under the same conditions gives only 33% effectiveness Toxicity and Fire Explosion Hazards are briefly discussed in Refs 11 12 Uses It can be used as a gelatinizer of collod cotton in commercial expls, but its high volatility is objectionable (Ref 2, p 208). Has been used in some rocket propints (Refs 11 12) Method of analysis of MeN is described by Vandoni (Ref 10)... 

Lead styphnate is a poor initiating explosive which when dry is very sensitive to friction and impact, to electrostatic discharge, and to flame. Its main use is as an additive to lead azide to improve flame sensitiveness (see p. 101). When pressed to a density of 2-6 g ml-1 it has a velocity of detonation of4900 m s l. 

Although the requirement for flame sensitiveness is the main consideration for initiating explosives for plain detonators, others are important in manufacture. The explosive must be capable of compression into a coherent mass and at the same time leave the equipment free from adhesions. Lead azide can be somewhat deficient in cohesion, and to improve this a small proportion of tetryl is sometimes added to the... 

Cannon fuse A coated, thread-wrapped cord filled with black powder designed to initiate flame-sensitive explosives. 

The different parts of a flame detector must be rigid. If bumping the gas chromatograph moves the collector momentarily by 0.1 mm, the capacitance between the collector and the rest of the detector may decrease (or increase) by perhaps 0.1 pF. If the collector is polarized at 300 V, this change in capacitance injects a spike of 30 pC into the electrometer. At the typical flame sensitivity, this spike is equivalent to a very narrow peak of half a pg, a readily detectable amount. The coaxial cable from the detector to the electrometer is also a capacitor sensitive to vibration. It also suffers from triboelectricity (charge... 

Flame sensitivity open fire, expln None None... 

Thus, when a new expl compd is first prepd in the lab it is essential for max safety that a series of preliminary tests be conducted to determine its order of sensitivity (See Physical Tests for Determining Esplosives and Other Properties, Vol 1, pp VII-XXVl). These tests are designed to determine whether the compd can be handled at all, and if so, with what care it must be treated. It is important that much less than lg (ca 0.2g) of solvent- wet or dissolved new expl be prepd, because for some expls even lg is more than sufficient to kill an unprotected person. For this reason, the tests referred to above should be conducted in the order aimatch flame sensitivity... 

A narrow spectral bandpass of ca. 0.2 nm is required with the 357.87 chromium line to eliminate nearby 357.66 nm and 358.23 nm argon lines when an argon-filled light source is used. In an air—acetylene flame, sensitivity and chemical interferences are critically dependent on flame stoichiometry and observation height. 

Willis (Wll), employing a sodium hollow cathode lamp, determined sodium in blood serum. With a 10-cm long flame, sensitivity was so high as to make the necessary dilution (500-fold) impractical and subject to contamination. He reduced sensitivity simply in shortening the absorption path by turning the flame 90 degrees, but he also showed that the use of another, much weaker resonance line at 3302 A reduced dilution requirements to only 10-fold. No interferences were encountered from any of the serum constituents. 

Allan (A7) during his studies of ashed plant materials also investigated interferences. Using an air-acetylene flame, sodium, potassium, calcium, magnesium, and phosphate had no effect. In the air-coal gas flame, as employed by Elwell and Gidley (E2), recoveries of iron were only 80-90% when the test solutions contained an excess of calcium, copper, aluminum, titanium, and zirconium. With silicon added, iron recovery was 26%. Owing to incomplete vaporization of iron in the flame, sensitivities attained are higher in the air-acetylene flame and lower in the air-coal gas flame. Since iron is subject to oxidation in the flame, fuel-rich flames are preferable. 

The diameter of the droplets produced by a pneumatic nebulizer varies from < 5 ixm to about 25 xm. The spray chamber allows droplets to reach the burner which can be vaporized and atomized in the flame. If the spray chamber prevents small droplets (diameter of about 10 tm or less) from entering the flame, sensitivity will be decreased. On the other hand, if large droplets (>10/x-m) reach the flame, the flame noise will increase and the temperature will decrease. From the total mass of the sample nebulized, the maximum useful amount of droplets is about 10%, which gives the limit for the maximum attainable efficiency of the nebulizer. However, the nebuliza-tion efficiency can be improved in various ways by altering the droplet size distribution. A bead or bar placed close to the orifice of the nebulizer, or a counter flow nebulizer can be used for this purpose (Figure 37). 

Flame sensitivity test single and a bunch of four fuses were hung vertically above the nitrate-o-ethylbenzene explosives, the distance between fuses and explosives were 5 mm and reduced gradually until they were contacted. Making... 

Above flash point, vapor-air mixtures are explosive within flammable limits noted above. Moderate explosion hazard and dangerous fire hazard when exposed to heal, sparks or flames. Sensitive to static discharge Fire Extinguishing Media ... 

One must also keep in mind that these experiments are measuring the temperature sensitivity of a particular composition, in which the entire sample is heated to the experimental temperature. Ignition sensitivity can, and must, also be discussed in terms of the relative ease of ignition of a small portion of a pyrotechnic material due to other types of potential stimuli, including static spark, impact, friction, and flame. Sensitivity is discussed further in Chapter 6. 

Caution The primary explosive is shock and flame sensitive. 

It can be clearly seen from Fig. 2.22 that the sensitivity of LA to flame is lower compared to other primary explosives. This is the reason why it is in some applications mixed with other primary explosives with high flame sensitivity, such as LS. 

The lead salt of 5,5 -azotetrazol is a powerful primary explosive that can be used as an initiator either alone or in a mixture. Its flame sensitivity is higher than that of lead azide and therefore PbAzTZ can be used in a mixture with lead azide to improve its flammability [90]. 

Zeldovich number Ze = E Th - To)IRI h, where E - efficient activation energy, R - gas constant, Th -flame temperature. To - temperature of unbumed mixture. Zeldovich number is a measure of flame sensitivity to disturbance. It is also used as a measure of hydrodynamic flow disturbance effect on detonation. It is often used as a combination Ze (Le - 1). 

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