| 摘要 |
PURPOSE:To suppress and average the variation width of frequency difference due to disturbance such as temperature variation by calculating the frequency difference by using a correction frequency calculated on the same time axis as time axis of a measured frequency. CONSTITUTION:A dry gas and a sample gas are flowed alternately to a crystal resonator which is provided in an oscillation frequency detector 1 and coated with an adsorbent material adsorbing component in the sample gas to detect oscillation frequencies f1 and f2 when the respective gases are flowed. Those frequencies are written in memory by CPU4 and then the CPU4 calculates correction f1c<n> and f2c<n> when the oscillation frequency varies in the order of f1<n>, f2<n>, f1<n+1>, and f2<n+1> from equations I and III. Then, the frequency difference DELTAf is calculated from equations II and IV and the concn. of a measured component is outputted to an analog output device 7 through a DA converter 6. |
