后向散射式路道能见度激光测量仪的研究

后向散射式跑道能见度激光测量仪主要由光学发射与接收系统、信号放大与处理系统及显示系统三部分组成。其中，光学发射与接收系统主要包括：Ｎｄ ：ＹＡＧ 激光器、倍频器、准直镜、扩束镜、光学接收镜头、截止滤光片、窄带干涉滤光片及光电转换系统等；信号放大与处理系统主要包括：小信号放大电路、延时电路、采样保持电路、多路模拟开关、模 数转换电路及８０３１ 单片机等；显示系统主要由数字显示器、打印机及接口电路等组成。介绍了该测量仪的工作原理、基本结构和主要技术指标，讨论了其中的技术难点及其相应的解决方法。

Study of the back-scattering laser detection instrument for runway visual range

A new kind of the measurement instrument for runway visual range using laser is presented. This instrument consists of three parts: optical emitting and receiving system, signal amplifying and controlling system, and display system. In detail, optical emitting and receiving system is mainly composed of ND:YAG lasers, frequency multiplier, collimator lens, extender lens, optical receiving lens, cot off filter, narrow band interference filter, focusing lens and photoelectric transforming system. The signal amplifying and controlling system is mainly composed of microsignal amplifier, delay circuit, sampling hold circuit, multichannel simulated switch, A/D converter and 8031 chip processor. And the display system is mainly composed of digital indicator, printer and I/O circuit. The principle, the structure and the main specifications of the instrument are introduced. The key technologies and the corresponding solution methods are discussed. Key words: runway visual range; laser detection; horizontal visibility; approach visibilityZhenwei MAO Structure Research Laboratory,University of Science and Technology of China,230026 Hefei Abstract In this paper,the theoretical alpha coefficients of L T equation were applied to the analysis of Pb,Cu and Sn in ancient bronze coins by X ray fluorescence spectrometry.The results obtained in this way are in agreement with those by the fundamental parameter method and the simulant standard samples method,because this method and the simulant standard samples method were both developed from the fundamental parameter method,and the standard samples are the same.The calculation of element concentration is simple and rapid,but the precision of the results depends relatively largely on the concentration range of the standard samples by this method.