瞄准距离对热喷涂粒子脉冲信号强度的影响

针对基于窗口调制和比色测温技术的热喷涂粒子参数测量系统，从理论上分析了瞄准距离变化对脉冲信号强度的影响，发现入射能量水平和信号特征的变化是影响实测脉冲信号强度的主要因素，二者的影响作用在小于理想瞄准距离时相反从而在一定程度上相互抵消，在大于理想瞄准距离时相同从而叠加，使得实测脉冲信号强度随瞄准距离的变化呈现不对称倒V形变化规律．实验验证与理论分析结果吻合良好，证实了用上述双机制复合作用解释瞄准距离变化时粒子脉冲信号强度变化规律的合理性。

Effect of Aiming Distance on Voltage Level of Signal Pulses Generated by Thermal Spray Particles

The effect of aiming distance on voltage level of effective signal pulses was theoretically analyzed for the measurement system based on window-modulating velocimetry and 2-color pyrometry to diagnose multiple parameters of thermal spray particles. It reveals that the incident energy level and the variances of signal characteristics are the two main factors affecting the voltage level of signal pulses. The two factors have a superimposed effect on the voltage level when the aiming distance is larger than standard 75 mm, or a neutralized effect when the aiming distance is smaller than 75 mm. Consequently, when the aiming distance varies from 45 mm to 120 mm, the voltage level demonstrates an asymmetrical inversed "V" shape variation. The experimental results are well coincident with the simulated ones to confirm the reasonability of the proposed mechanism.