| 摘要 |
PURPOSE:To improve greatly the S-N ratio by analyzing frequency component of detecting signals from a detecting mechanism, and signal treating in an optimal frequency region to focus accrurately. CONSTITUTION:It is necessary to select and change the differential frequency region of a differentiation mechanism depending on the kind of samples to analyze detecting signals, accordingly a differentiating mechanism 7 to differentiate detecting signals depending on the frequency component with time and a frequency detecting device 8 connected to the detecting mechanism 6 through a switch SW to analyze the frequency component of detecting signals and to select and change the differential frequency region of the differentiating mechanism 7 depending on the analyzed results are connected to the detecting mechanism 6 in parallel to each other. The differentiating mechanism 7 is constituted with four differentiators 7a-7d, differential frequency regions of them are different from each other, and with switchs 7a'-7d' connected to each input terminal. Each differentiator is provided with the gain characteristics in which the cutoff frequency is successively shifted to higher frequency. |
