Ignition wire

DuPont—Dow is the primary suppHer of these polymers. There is an estimated 18,000 t of these elastomers used per year. The main uses of CPE are in constmction, automotive, and electrical appHcations. These include power steering hose, electrical cords used in low voltage appHcations (extension cords, ignition wire), pond liners, and as a plastic modifier to improve impact modification. 

On a Squib operated system, the igniter wire can be supervised but condition of explosive is not known. 

Most static-bomb calorimeters used are of the isoperibol type, such as the one in figure 7.1. Here, the bomb A is a pressure vessel of 300 cm3 internal volume. Combustion bombs are usually made of stainless steel and frequently have an internal platinum lining to prevent corrosion. In a typical high-precision experiment, the platinum ignition wire B connects the two electrodes C, which are affixed to the bomb head. A cotton thread fuse D (other materials such as polyethene are also used), of known energy of combustion, is weighed to a precision of 10-5 — 10-6 g and tied to the platinum wire. A pellet E of the compound... 

LA, Silver Gold Fulminates, and AuNHCl, under pressures of 5000 kg/cm2, can be initiated by an igniting wire to complete decompn. Secondary expls were found to undergo combustion w/o mechanical effect even at 10,000 kg/cm2... 

Navy Hand Signal Flare was cardboard tube 12% inches long filled with a flare mixture and fixed on a wood handle. The flare was ignited by a pull igniter wire which extended down the tube (p 241, Fig 393 of Ref 1) ... 

Figure 3.1 A typical calorimeter bomb for use with pure oxygen. The sample dish, igniting wire, and oxygen port are clearly visible. Not shown is the insulated water bath in which the bomb is immersed. There are facilities for stirring and accurately measuring the temperature of the water (Reproduced from Jessup, R.S., J. Res. Nat. Bur.

If one is planning to use a battery to heat the ignition wire, the next step is to take one of the igniters for a test run. Simply wire... 

Once a suitable power source has been determined, it s time to move onto cap assembly. First one puts the igniter wire into the cap. It should be positioned along the wall of the cap body so there is room to add other ingredients to the cap. Next add enough reloading powder to fill the cap about one-quarter full. The relatively safe part of the job is now done. From here on out, it s into the danger zone ... 

Finally, take each leg of the igniter wire, and position it on opposite sides of the Q-Tip shaft. Cut a section of speaker wire roughly one inch long. Pull the wire out of it, then with a razor blade slit it down the middle so that one has two separate hollow insulator tubes. Slide these tubes down the two legs of the igniter wire until half of it is inside the cap body, and half outside. Then with a pliers crimp the top of the cap body loosely shut so that the wires, the Q-Tip, and the insulators are held firmly in place. Then apply some bathtub caulk around the top of the cap so that everything is sealed in place. 

Figure 15-9 A bomb calorimeter measures q, the amount of heat given off or absorbed by a reaction occurring at constant volume. The amount of energy introduced via the ignition wires is measured and taken into account.

The rocket motors must be handled manually, so exposure to lead is a possibility. The motors must be loaded into firing racks. Ignition wires must be connected to the igniters, and new igniters might need to be installed. 

More widely used is the adiabatic bomb calorimeter, shown in Figure 5. The sample is placed in the crucible, in contact with an ignition wire. The crucible is placed in a strong bomb of stainless steel, which is sealed firmly and pressurised to about 25-30 atm with oxygen. The bomb is placed inside a container with a measured amount of water. This is carefully supported within a shielding container with an outer jacket. This shield contains an electrically conducting solution with a heater, or some other means of temperature control. Thermistor sensors measure the temperature of the inner eontainer, and of the outer jacket. Having... 

Corrections for the burning of the ignition wire, and for the conversion of any nitrogen in the sample into nitric acid should be applied. 

Figure 4.30 illustrates the liquid calorimeter. It also operates in an isoperibol manner. The cross-section represents a simple bomb or reaction calorimeter, as is ordinarily used for the determination of heats of combustion [8]. The reaction is carried out in a steel bomb, filled with oxygen and the unknown sample. The reaction is started by electrically burning the calibrated ignition wire. The heat evolved during... 

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