| 摘要 |
<p>A novel method for measuring a deposit point is provided, which makes it possible to quickly and accurately measure a cloud point. A test sample is irradiated at an angle of incidence &thetas; with an incoming light beam which satisfies an expression &thetas; < &thetas;2 while gradually cooling the test sample such as gas oil, and a totally reflected light beam from the test sample is detected for every temperature, provided that &thetas;2 represents a critical angle of total reflection of a deposit such as a paraffin component deposited when the test sample is cooled. The deposit point of the test sample is determined from change in intensity of the totally reflected light beam with respect to the change in temperature. The light intensity distributions detected by a sensor array at respective temperatures are statistically processed to more accurately determine the deposit point. It is possible to use a total reflection type sensor having a waveguide structure formed with a light-incoming optical path and a light-emitting optical path. CCD is used as a detector. <IMAGE></p> |
