Pyrotechnics light-generating

Many of the newly developed pyrotechnics are based on metal complexes with very nitrogen-rich ligands, mainly tetrazole derivatives (Fig. 2.17). Unlike conventional 

Since environmentally compatible pyrotechnics should not contain perchlorates or heavy metals in the first instance, new red and green formulations are being developed which contain Cu instead of Ba and whieh eontain other oxidizers (e.g. nitrate or dinitramide. Fig. 2.17) instead of perehlorates. The high nitrogen content also guarantees a significant reduction of the smoke and particulate matter released and consequently results in a considerably higher color brilliance. 

Furthermore, high-N red and green formulations show an increase in burn time, an increase in luminous intensity and an increase in spectral purity. Two examples of new red and green formulations developed by ARDEC/LMU are  

In the above mentioned red and green formulations it is possible to replace the high-N metal tetrazolate salt with more metal nitrate and free aminotetrazole. This causes longer burn times but lower intensities. 

The strontium formulation shows a reasonably high red color purity as can be seen from the chromaticity diagram in Fig. 2.19a. The color purity (Pe) of a visible flare with the chromaticity (x, y) is its difference from the illuminant s white point relative to the furthest point on the chromaticity diagram with the same hue (dominant wavelength for monochromatic sources) where (x , y ) is the chromaticity of the white point and (xi, ji) is the point on the perimeter whose line segment to the white point contains the chromaticity of the stimulus. 

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Ellem (Ref 138, p 181) also describes pyrotechnic means of producing explosive and whistling sound. Recent advances in the art of generating oscillating light signals are described in Section 8 of this article... 

To produce this type of atomic emission in a pyrotechnic system, one must produce sufficient heat to generate atomic vapor in the flame, and then excite the atoms from the ground to various possible excited electronic states. Emission intensity will increase as the flame temperature increases, as more and more atoms are vaporized and excited. Return of the atoms to their ground state produces the light emission. A pattern of wavelengths, known as an atomic spectrum, is produced by each element. This pattern - a series of lines - corresponds to the various electronic... 

Pyrotechnic compositions containing a barium compound and a good chlorine source can generate barium monochloride, BaCl, in the flame and the emission of green light will be observed. BaCl - an unstable species at room temperature - is an excellent emitter in... 

Place a small pile of the mixed composition on the fireproof board, insert a section of safety fuse into the base of the pile, and carefully light the end of the fuse with a match. Step back and observe the effect. Because of the generation of smoke by most pyrotechnic compositions, these tests are best conducted outdoors or in a well-ventilated area such as a laboratory fume hood. 3e certain no flammable materials are near the test area, for sparks may be produced. 

The term "pyrotechnics" in English also means the technology of pyrotechnics and is defined as "technology to utilize chemically-generated light, heat or sound for amusement, utility or warfare" 7). ... 

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