| 摘要 |
PURPOSE:To shorten a measurement time and to reduce the size of a measuring instrument by irradiating a group of sprayed particles with a laser beam, converting light scattered by the atomized particle group and photodetecting it by a photoelectric element, and calculating particle size instantaneously on the basis of a current signal obtained by the photoelectric element and displaying it digitally. CONSTITUTION:The laser beam irradiated by a laser beam oscillator 1 is collimated by a collimator lens 2 into parallel laser beam 3, which illuminates the group 3 of sprayed particles to be measured. An optical lens 5 is provided to converge light transmitted or scattered by the particle group 3 and photoelectric converting elements 6 and 7 are arranged concentrically at the focus position of the lens 5. Current signals from the elements 6 and 7 are amplified by logarithmic amplifiers 8 and 9 which have the same characteristics and inputted to a subtracting circuit 10. The output of the circuit 10 is inputted to a computing element 12 through an A/D converter 11 and the arithmetic result is displayed digitally on a display device 13. Thus, the measurement time is shortened and the size of the instrument is reduced. |
