| 摘要 |
PURPOSE:To simplify the device and the method for measuring a clouding point by detecting surely the initial time of the occurrence of cloud in accordance with a sudden change in the quantity of received light of a photoelectric detector at the cloud occurrence time. CONSTITUTION:The measuring device consists of a test tube 1 whose inside bottom face 1a or outside bottom face 1b is finished to a specular surface, a metal bath 2 loaded in a cooling tank 3, a cover part 4, a temperature detecting end 5, a sensor unit 8 where a pair of a light projector 6 and a photodetector 7 are joined into one body, and optical fibers 9 and 10. The quantity of received light converted to a photocurrent or photovoltage by the photodetector 7 is stored in a computer. A forecasted clouding point is set to the computer, and the temperature of a sample S is reduced gradually, and pulse-like light is emitted from the light projector 6 through the optical fiber 9 each time when the temperature is reduced by 1 deg.C, and the reflected light is converted photoelectrically through the optical fiber 10 and the photodetector 7 and is compared with the value stored in the computer. Cooling is stopped when the photoelectrically converted value is lower than the preliminarily set value, and the integer value of temperature display obtained at this time is defined as the clouding point. |
