| 摘要 |
PURPOSE:To attain automatically an overall automatic calibration by detecting scattered light of air molecule generated simultaneously in an irradiating area for detecting a particle in an air sample and executing an automatic calibration. CONSTITUTION:Pulse light being scattered light by particle and DC light being scattered light by air molecule are made incident to a photoelectric element 1 from an irradiating area. Accordingly, an output of a pre-amplifier 2 becomes a waveform formed by superposing a component of the pulse light on a component of the DC light. An output of the amplifier 2 consisting of such a waveform is divided into a pulse signal and a DC signal by the first and the second amplifiers 3, 4, and they are amplified, respectively. Subsequently, the pulse signal being an output of the amplifier 3 is inputted to a wave height analyzing circuit 5, and an essential particle counting is executed. In this way, an overall automatic calibration containing a variation of a condensing rate of a condensing optical system, a time aging of a photoelectric element, etc. is attained automatically. |
