| 摘要 |
PURPOSE:To increase the detection accuracy for the soidum ionization detector by drawing out only the fluctuation width of the ion current to change it into the detection signal. CONSTITUTION:Load resistance 7 is provided between collector 5 and high voltage DC power source 2, and at the same time HPF8, RMS operator 9 and display part 10 are provided at the output side of resistance 7. Thus a detector is formed. In such way, the output voltage across the load resistance draws out first only the fluctuation component through HPF2. Then the necessary operation is given by operator 9 to obtain the amplitude mean value in the form of the DC output for the fluctuation component within the fixed time T. This DC output undergoes the comparison process at part 10 to have the direct display or alarm. In such way, the dark current component featuring the reduced fluctuation is cut off to eliminate the error caused by the dark current, thus increasing the detection accuracy. |
