Length and duration of flame test

Length and Duration of Flame Test(Gr5sse und Dauer von tengstoff-Flammen Probe, in Ger). See Flame Teat... 

Flame Tests. See Flame, Length and Duration of , Flame Photometry , Flame Propagation and Velocity and Flame Temperature Measurements , in (his Vol Also in Vol 1 Flame Test , p XII ... 

Flame Test(Length and Duration of Flame Determination) (Gross und Dauer von Spreogstoff-Flommen ... 

SAFETY PROFILE Permissible explosives are essentially high explosives (dynamite) modified by the introduction of dopes. The function of the dopes in general is to decrease flame temperature, and to a smaller extent, the length and duration of flame, when the explosive is converted from a solid into a gas, i.e., when it is fired or detonated. The designation permissible is given to an explosive of modified dynamite tjqje after it has passed certain tests designated by the Federal Bureau of Mines. The permissible character of such explosives depends not only upon the ingredients in the explosive, but also on certain well-defined specifications as to... 

ASTM D 470-81 uses the same test chamber with a 254 mm long piece of wire mounted horizontally between two clamps at 203 mm from one another. The wire is ignited by a 102 to 127 mm long flame for 30 s. Cotton wool is placed 240 mm below the ignition point. The length and duration of burning is observed and it is recorded whether the cotton has flared up. 

The specimen (a complete unit, its sub-assembly or component) and the test conditions (the material in the normal environment or underlaid with a pinewood board covered by tissue paper) are identical to the former standard. The igniting source is a 35 mm long burner tube with a bore of 0.5 0.1 mm and an outer diameter not exceeding 0.9mm(e.g. a hypodermic needle with the tapered end cut off). In the vertical position of the burner, the length of the flame is adjusted to 12 1 mm. The test flame is applied at 45 deg. to the specimen, in most unfavourable position of normal use (Fig. 3.119) preferably for 5, 10, 20, 30, 60, or 120 s. The exact site and duration of ignition may be given by the relevant specification of a particular product. Unless otherwise specified, the specimen is considered to have withstood the needle-flame test if one of the following four situations applies ... 

The flame-test apparatus used at the US BurMines Explosives Experiment Station at Bruceton, Pa consists essentially of a cannon in which an explosive is fired or detonated. The cannon, identical widi that employed for the ballistic pendulum,ia mounts vertically on a concrete foundation located ia a dark building. By means of a photographic camera equipped with auitable devicea to cot off all extraneous light rays, the flame ia continuously obaetved such that its apex is in the field of view. The flame is recorded on a sensitixed film wrapped about a drum that revolves at a predetermined rate of speed. The length of each flame is indicated by its hei t in the photograph, and the duration by the length of photograph... 

In this test, specimens measnring 125 mm in length and 13 mm in width are snspended vertically and clamped at the top end. A thin layer of cotton is positioned 300 mm below the test specimen to catch any molten material that may drop from the specimen. A 20-mm-long flame from a methane burner is applied to the center point on the bottom end of the specimen. The burner is positioned snch that the burner barrel is located 10 mm below the bottom end of the material specimen. The flame is maintained for 10 s, and then removed to a distance of at least 150 mm. Upon flame removal, the specimen is observed for afterflaming and its duration time recorded (fi). As soon as the afterflame ceases, the burner flame is reapplied for an additional 10 s, and then removed again. Durations of afterflaming ( 2) and/or afterglowing (ts) are noted. On the basis of the results. 

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