| 摘要 |
<p>Means for measuring parameters associated with particles is disclosed. A laser (25) is provided for generating a pair of coherent laser beams (32, 34). These beams are directed along an axis and cross to define an interference pattern constituting a sample volume (16). A collection apparatus (46, 48, 50) for sensing light scattered by particles or the like within the sample volume (16) is provided. The collected light is directed onto photodetectors (50) which are coupled to signal phase determining means (54) for measuring the relative phase between the signals from each photodetector (50) and signal amplitude determining means to measure the relative amplitude of the signals. Sizing means (56) are coupled to the signal phase (54) and amplitude measuring means for determining the size of the particles. Means are disclosed for determining the change in the effective cross-section of the sample volume due to size variations of the particles passing through the sample volume (16).</p> |
