Spark sensitivity, electric

Primary explosives differ from secondary explosives in that they undergo a rapid transition from burning to detonation and have the ability to transmit the detonation to less sensitive (but more powerful) secondary explosives. Primary explosives have high degrees of sensitivity to initiation through shock, friction, electric spark, or high temperature, and explode whether confined or unconfined. Some widely used primary explosives include lead azide, silver azide, tetrazene, lead styphnate, mercury fulminate, and diazodinitrophenol. Nuclear weapon applications normally limit the use of primary explosives to lead azide and lead styphnate. 

Hexanitrostilbene or HNS (C14H6N6012) is a heat-resistant yellow crystalline solid explosive. HNS is also resistant to radiation, insensitive to electric sparks, and less sensitive to impact than tetryl. It is used in heat-resistant booster explosives and has been used in stage separations in space rockets and for seismic experiments on the moon. Its melting temperature is 316 °C.12... 

Black powder is the oldest explosive in history, dating back to the eighth century. Its chemical composition is well-known as a mixture of potassium nitrate, sulfur, and charcoal. The mixture ratio is varied according to the purpose for which it is to be used, with the ranges kno3(0-58-0.79), (0.08-0.20), and ( (0.10-0.20). Black powder composed of particles less than 0.1 mm in diameter is used for shell burst of fireworks and fuses. The grade with diameter 0.4—1.2 mm is used for the launch of spherical shells of fireworks, while that with diameter 3-7 mm is used in stone mines. Since black powder is sensitive to sparks caused by mechanical impact, friction, and static electricity, black powder containers should be made of brass or aluminum alloys rather than iron or steel. When Cl and Ca or Mg are present as impurities, CaClj or MgClj is formed and the thermal performance of KN is reduced. Contamination with NaCl also needs to be avoided for the same reason. 

Electric Spark Sensitivity to. MF is capable of being ignited by a spark from a person charged to less than 5000 volts, a condition that is possible in plant operations. Brown et al (Ref 27) give for Sensitivity to Electrostatic Discharge 0.025 joules (Ref 34)... 

Rate of Detonation. See Detonation Race Rifle Bullet Impact Test — not found Sand Test. See under Brisance Sensitivity to Electric Spark or to Electrostatic Discharge. See under Electric Spark Sensitivity to Initiation — not found Sensitivity to Pressure. When pressed at pressures in excess of 25000psi,. MF will... 

For a fixed distance, sparking occurs at a critical voltage leading to smoke, flame, flash, crackling, decomposition, ignition or explosion. This critical voltage is a measure of electric spark or electrostatic discharge sensitivity of the explosive under test [71-73]. 

The most important characteristic of a delay formulation is its IBR. In addition, other important characteristics are sensitivity to impact, friction and electric spark, ignition temperature, heat output and gas output. Therefore, before static evaluation of delays, the delay formulation must be characterized thoroughly for these properties. 

As discussed under explosives and propellants, a number of energetic binders GAP, NHTPB, poly(NiMMO), poly(GlyN), poly(BAMO), poly(AMMO) and BAMO-AMMO copolymers etc. have been reported in the recent past and are at various stages of development and introduction for bulk production of explosives and propellants for various applications. These polymeric binders are reasonably stable and are of established compatibility with a wide range of ingredients used for explosive and propellant formulations. The data on their explosive properties impact, friction and electric spark sensitivities, indicate that it is safe to handle these materials. However, there appears to be no report in the open literature on... 

Primary explosives are a group of substances which are highly sensitive to the action of mechanical shock and are readily ignited by direct contact with flame or electric sparks. 

High ignitability by direct action of a flame or electric spark is a characteristic feature of lead styphnate. The salts enormous sensitiveness to the discharge of static electricity was first disclosed in 1938 by Barcikowski, Dobrzynski and Kielczewski [541. 

Ignition - much more easily ignited by flame or electric spark than MF, LA or DADNPh (Ref 24, p 7-12) Impact Sensitivity, BM App,... 

The BurMines criteria for racing the potential explosion hazard of dust by the standard electric spark is defined by the ignition sensitivity, explosion severity and the overall explosibility indices or the correlative adjectives, weak, moderate, strong and severe (Ref 10)... 

Primary explosives have a high degree of sensitivity to initiation through shock, friction, electric spark or high temperatures and explode whether they are confined or unconfined. Typical primary explosives which are widely used are lead azide, lead styphnate (trinitroresorci-nate), lead mononitroresorcinate (LMNR), potassium dinitrobenzo-furozan (KDNBF) and barium styphnate. Other primary explosive materials which are not frequently used today are mercury azide and mercury fulminate. 

HNS [hexanitrostilbene (C14H6N6012)] (2.17) is known as a heat-resistant explosive and is also resistant to radiation. It is practically insensitive to an electric spark and is less sensitive to impact than tetryl. Some of the properties of HNS are shown in Table 2.18. 

TNT, like RDX and Composition B, is not classified as dangerous with respect to hazard from electric sparks. Sensitivity to electrostatic discharge of TNT (thru 100 mesh) is 0,06 Joules (unconfined) and 4.4 Joules (confined) TNT can be detonated by electric discharge (Ref 108)... 

Composite propellants. A composite propellant represents a group of propellants in which the composites, the fuels, and the oxidizers are separated materials. This type of propellant has replaced the sensitive propellants that suffer from the possibility of accidental initiation from fire, impact, electric spark, and others [4-6],... 

---