Apparatus for Determining the Temperature of Ignition

The copper bar (a) had a circular enlargement at-one end in which there were five holes the central one (F) contd mercury in which the bulb of a thermometer was immersed a small copper tube, contg O.lg of pulverized explosive to be tested, was placed in each of the other holes. The bar was supported on a stand and was heated by means 

Note 1 Instead of heating the bar by gas burners, it can be heated electrically, such as described by E. Berl G. Rueff in Cellu-losechemie 14, 43 (1933). The bar, known as Bloc Maquenne, generally used in France for determining melting points, could be adopted for use in determining the ignition (or. explosion) point 

Note 3 Hot bar and other methods for determining ignition (or explosion) temperature are described in the following refs Refs 1) A.P. Sy, JFrankllnst 155, 171 (l 903) (Early US Ordnance method, also described in Refs 2 4) 2) Marshall 2 (l917), 434-35 (same method as in Ref 1) 3) Marshall 2 (1917), 435 (Hot bar method) 4) Reilly (1938) 83 (same method as in Ref 1 is listed as Deflagration Test) 5) PATR 2700, Vol 1 (1960) pp XVl XVII (description of two tests and list of 11 refs) 6) AMCP 706-177 (1971), p 3 (current US Ordnance Explosion Temperature Determination) 7) PATR 2700, Vol 6 (1973) p E387-R (Explosion Temperature) 

Hot Extrusion of Shells. A modification of the Ugine-Sejournet hot extrusion process (using glass as lubricant) is used by Scaife Company of Oakmont, Pennsylvania. In this process a complete shell (such as 4.2 inch) can be produced in one piece from a simple billet. Important features of the development are in the substitution of readily available billet stock for seamless steel tubing, a critical material in times of war. Another feature of this process is that it requires about 25% less steel Refs Ordnance, 38, 753 (1954) 2) Iron Age 

Introduction. A hot spot is a localized region of higher-than-average temperature. In explosion phenomena, the term hot spot is usually associated with the name. of Bowden, although many other- investigators have invoked the concept and contributed to its understand mg 

Note 2 Fisher Melting Point Apparatus, described by Fisher Scientific Co, Pittsburgh, Pa (1970), p 640, can also be used for determining ignition (or explosion) temperature 

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