Card-gap test

Reactivity (instability) information Acceleration rate calorimetry Differential thermal analysis (DTA) Impact test Thermal stability Lead block test Explosion propagation with detonation Drop weight test Thermal decomposition test Influence test Self-acceleration temperature Card gap test (under confinement) JANAE Critical diameter Pyrophoricity... 

Card Gap Test. Results are given on NMe and mixts of NMe with TeNMe. A mixt having a slightly neg OB gave the highest value of 75 cards (Ref 35), Another gap test is given in Ref 22 with a donor charge of 50g of PETN/Mn 95/5 the max gap for deton transfer was found to be 3mm... 

An 87 13 mixt with benz gave a Trauzl test of 134% of TNT (Ref 26). Mixts of from 65 to 90% by wt in benz had a card gap test of over 300 cards, indicating them to be very sens (Ref 36). The sensy of mixts with benz was found to be due to the formation and collapse of cavitation bubbles in the liq (Ref 43) Ethylene Glycol. A 50% soln by wt had a card gap test of 270 cards (Ref 36)... 

A mixt contg 40% TeNMe had a card gap test of 75 cards (Ref 36)... 

Detonation Rate, For both mixts at 0°, 6900m/sec BurMines Card Gap Test. For both mixts, over 2000 mils... 

Card Gap Test. Freeze dried UFAP, 0 cards jet milled UFAP, 0-4 cards and slurry ground UFAP, 8-10 cards (Ref 48, p 56)... 

Self-acceleration temperature Card gap test (under confinement) lANAF... 

Cachia, G. P. und Withebread, E. G. The Initiation of Explosives by Shock, Proc. Roy. Soc. A 246, 268-273 (1958). Card-Gap Test for Shock Sensitivity of Liquid Monopropellant, Test Nr. 1, Recommended by the JANAF Panel on Liquid Monopropellant Test Methods, March 1960 Amster, A. B., Noonan, E. C. und Bryan, G. J. Solid Propellant Detonability, ARS-Journal 30, 960-964 (1960)... 

Card-Gap Test for Determination of Sympathetic Detonation. See under Detonation by Influence and also Refs 40, 47, 48, 54 58 under Detonation, Experimental Procedures... 

Card Gap Test. See Refs 40 58 and also under GAP TESTS Cathode-Ray Oscillograph Photography. See Concrete Block Test. Fr test similar to Trauzl test, but using concrete instead of lead block. See Vol 3, p C495-L... 

Card Gap Test , "Four Cartridge Test , "Shock-Pass-Heat-Filtier (SPHF) Plate Test ,... 

T.P. Liddiard, Jr Donna Price, "Re-calibration of Standard Card-Gap Test , NOLTR 65-43(1965) [Gap tests, used to... 

Booster-Gap Explosive Sensitivity Test of Cole Edwards, described in detail in USP 2832213(1958) (Ref 17). It was claimed to be more reliable and less ex. pensive than the card test (See after "card-gap test") and the three-legged table test, described here after "shock-pass-heat-filter test . The "booster-gap test serves for evaluating shock sensitivity of liquid explosives. It includes a set of snug-fitting telescopic cardboard tubes (ca 1 inch diam) and a cylindrical wooden block for holding the electric blasting cap, Tetryl booster pellet, circular spacer cards, and the cup with liquid explosive (to test) fit compactly in the cardboard tubes when... 

M.A. Cook et al, JApplPhys 30, 1579-84(1959) (Instrumented Card-Gap or SPHF-Plate Test) 23) Baum, Stanyukovich Shekhter (1959). 754-71 (Deton by influence thru air) 771-78 (Deton by influence thru condensed media) 778-81 (Safe distances for propagation of deton betw some expl chges used in Rus coal mines) 23a) Liquid Propellants Info Agency, Applied Physics Lab, Johns Hopkins Univ, "Liquid Propellants Test Methods, Test No 1, Card-Gap Test for Shock Sensitivity of Liquid Monopropellants (March i960)... 

The three propellants listed in Table I have been tested in the cured state and classed propellant explosive (solid) Class B by the Interstate Commerce Commission (6). The aluminized formulation, Arcite 373D, gave the same test results when uncured. In addition, Arcite 373D and Arcite 386, both cured and uncured, tested zero cards in the standard Naval Ordanance Laboratory card-gap test (I, 2). 

Larger Scale Testing. The standard card gap test (2) is test No. 1 of a series of larger scale tests designed to determine the sensitivity of liquid propellants to hydrodynamic shock. In this test, relative sensitivities of various propellants are determined in terms of the number of 0.01-inch thick cellulose acetate cards required to attenuate a standard shock sufficiently just to prevent initiation in the test sample. When performed according to the exacting conditions of apparatus and procedure, the results are very reproducible from one laboratory to another. However, small variations in the apparatus or procedure can cause major variations in the resulting data, and therefore the test can be considered only relative. A major drawback of the standard test is that it cannot accommodate materials that are volatile under the test condition. At TCC-RMD some special equipment has been developed that allows tests to be made on confined samples at elevated temperature and pressure. 

In the Trauzl test, the mixture produced an expansion of 24 cc./gram, which is indicative of a high energy reaction. Card gap tests were also positive the value at room temperature is approximately 25 cards. From these results it was concluded that a mixture of methylene chloride with nitrogen tetroxide constitutes a definite explosive hazard. This conclusion was not immediately apparent as a result of compatibility and impact testing alone. Methylene chloride was not recommended as a solvent for cleaning N2O4 systems instead, a water flush is used for this operation. 

The card gap test is one of the important tests that has been accepted by the explosives industry to distinguish between a material classified as mass detonating, Military Class 1.1, and a material classified as a fire hazard only, Military Class 1.3 (Ref 47). The card gap test has been described in earlier sections (Vol 6, GI3-R ff), as have other tests on detonation and explosion criteria (Vol 4, D299-R ff) Electrostatic Sensitivity Tests... 

Since ADN can detonate, there is a safety issue with ADN-based formulations. Particularly in the US is this seen as a major obstacle to using ADN formulations. The US requirement is that only compositions falling in the category 1.3 according to the UN rules for transportation can be considered. So far no published ADN composition falls into this category. ADN compositions normally fail in the UN card gap test, which is one of the compulsory tests for group 1.3. Consequently the focus in US is on finding less sensitive formulations of ADN. 

Suzuki, Kato, Fukuda et al. have conducted drop hammer sensitivity tests, friction sensitivity tests, and card gap tests on composite propellants that include nitramine 18 . The authors have conducted safety evaluations in cooperation with engineers from Nippon Oils and Fats Corporation to prove that no detonation propagation exist in composite propellants. We used new evaluating methods 11 131. The outline of our study follows. As new methods were constantly being adopted for the study, our tests were conducted on trial-and-error basis. All of the tests described here are not necessary for the evaluation of the detonating feature in composite propellants. 

Tlie transmission distance of picric acid charges was examined by Burlot [22]. This is however outside the scope of the present book. Also the method of determining the transmission detonation througli an inert solid medium, such as a number of card-boards ( card-gap test ) [116, 117], cellulose acetate [121, 122] or Plexiglas layer is discussed in the literature on the theory of detonation, for example [34]. 

Galvanic cells 9(i Gap rest. <26-.522 (HI 4351 card gap test. 522 dependence tm temperature 522 examination with, the ability of explosives to deflagrate 525 Gas bubbles, role of. in expl(wives. 347. 

Cadmium azide 462. 4X6(1II/IK6 Calculation of properties of explosives 2 Carhamoyl azides 469 Card-gap test see Cap test Carht Ao, 544... 

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