Papers by Keyword: Laser Scattering

Abstract: With the purpose of accurately and reliably making a forecast on fire, it is necessary to study the scattering properties of the early smoke particles. Based on the laser scattering principle of smoke particles, a device is designed in combination with aspiration system, semiconductor laser of different wavelength and spectral photoelectric receiving tube as well as the flexible structure and signal processing methods, so as to implement the function of acquiring the laser scattering intensity data of smoke particles from multiple angles. In this paper, through a comparative analysis, the basic data related to the smoke particle detection algorithms is obtained.

Abstract: It is well known that colloidal powder particles (between 1 mm and 0.001 mm) tend to agglomerate due to electrostatic forces. Then assuring an optimal dispersion condition is essential for good particle-size analysis results, since aggregates or weak agglomerates can be measured as single particles. In this paper the particle size distribution of an alumina powder A1000SG (ALCOA) was measured using distinct dispersion procedures. Distilled water was used as dispersant liquid in the pure state and with additives (citric acid and Duramax D-3005). Dispersion by supersonic vibration was also investigated, but only the application time was varied. Particle size analysis was accomplished by laser scattering technique and the dispersion condition was evaluated through zeta potential. The results showed that the Duramax’s electrosteric impediment is more efficient than citric acid’s electrostatic force, thereby providing better dispersion. Although useful, the supersonic vibration was not good enough to assure an optimal dispersion, at least for the material tested here.