Wu Tao1£¬Li Changjiu2
(1.School of Architectural Engineering and Mechanics,Xi'an¡¡Jiaotong¡¡University,Xi'an 710049,China;2.School of Material Science and Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
Abstract£ºA newly established method was applied to the data processing of theoretically simulated signals and experimentally measured signals to evaluate its accuracy and applicability£® A joint preprocessing method including null-shift elimination by low-pass filtering compensation and noise reduction by multiple neighboring points averaging is suggested,and a voltage criterion of the effective pulse based on the proposed noise reconstruction method was used to determine the position of the effective pulse and to extract the minimal measurement data concerning to the individual effective pulse.The type I trapezoid signal was approximately treated as an isosceles trapezoid and mathematically described by a piecewise function with 5 independent parameters.The least square fitting method combined with linear expansion and gradient-search algorithms was used to obtain the parameters of the piecewise function£® The fitted results show that the original geometrical characteristics of the measured pulse are precisely outlined,therefore,the key parameters of in-flight particles,such as velocity,surface temperature,diameter,etc£®,are statistically calculated by the fitted parameters with acceptable accuracy£®
Keywords:thermal radiation;thermal spray;effective signal pulse;data processing; particle parameter