| 摘要 |
The invention concerns a method and apparatus for classifying particles , and in particular for classifying particles according to whether they are diamond or non-diamond particles. In the method each particle (24) is irradiated with a pulse of monochromatic light capable of causing Raman spectral activation in certain particles. Light emitted by the particle is filtered to remove components which are outside a band including a characteristic Raman spectrum for the relevant class of particles. The filtered light is direct onto a light sensitive switch (26) which is arranged to close on receipt of filtered light of predetermined intensity. On closure of the light sensitive switch, an electrical pulse is generated and directed towards a pulse detector (32). The particle is classified according to whether or not the pulse detector (32) detects an electrical pulse within a predetermined time window. The original pulse of monochromatic light can be split into a test portion, used to irradiate the particle, and a control portion used to control a time gating apparatus which sets the time window. The method can be used in a particle sorting method in which, typically diamond and non-diamond particles are separated from one another.
|
