它激发式高频发生器常见故障及排除

Normal Trouble and Troublshooting of FR Power Generator

高频发生器是等离子体光谱仪的重要组成部分，其功率输出的稳定性对仪器的影响较大。常见的高频发生器分自激振荡式和它激振荡式两种，频率为２７．１２ＭＨｚ或４０．６８ＭＨｚ，最大输出功率为１．５－３ｋＷ．自激式高耗发生器结构简单，均由整流电源、振荡回路和电子管放大器组成，制造调试比较容易，但是频率及功率稳定性差。而它激式高频发生器由于是利用石英晶体的压电效应构成振荡器，频率稳定度高，耦合效率及性能较好，功率输出易于自动控制，但仪器线路复杂，放电回路电学特性的任何微小变化，就会导致阻抗失配，光谱仪不能正常工作，为此，日常维护及调试它激式高频发生器尤其显得重要。

RF power generator is an important part of the ICP-AES. The stability of power output is the chief factor that influences the instrument condition. There are two kinds of commom RF power generator,the self-excitative generator and the independent excitative generator. Their freqencies are 27. 12 MHz and 40. 68 MHz respectively, and the maximum output power is 1. 5 -3kW. The self-excitative RF power generator is simple in structure, which is composed of reetifiersource,oscillating circuit and value amplifier. It is easy to manufacture and adjust, but the stability of the freqency and power is not so good. Since the application of quarts’piezoelectric effect, the independent excitative RF generator has better stability,satisfied coupling officiency and charateristics, and the automatic control of the output power is easy to achieve. But this kind of generator has a complex circuit. Every little variation of the electricity charactor of the discharge loop would cause impedance dismatching . then the ICP-AES could not run normally. For this reason, it is very important to maintain and adjust the independent excitative RF power generator in good state.