Method and apparatus for determining phase transition temperature using laser attenuation
AssigneeMobil Oil Corporation
InventorGary J. Green
Life of this patent
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Abstract
Disclosed are methods and apparatus for determining phase transition temperatures and, more particularly, for determining cloud, fluidity, freezing, and haze points of hydrocarbon fuels and hydrocarbon/oxygenate fuel blends. The attenuation of laser light as it passes through the sample, then through a laser line filter, and then into a photodetector is used to determine the transition temperature.
Claims24
An apparatus operable in a plurality of ambient lighting conditions for determining the phase transition temperature of a liquid hydrocarbon fuel sample, said apparatus comprising:
- (a) a container for holding the sample and for providing an optical pathway therethrough;
- (b) a light source for projecting a highly parallel beam of monochromatic light along said optical pathway, said light having a wavelength in the visible spectrum;
- (c) means for detecting the intensity of said light exiting said optical pathway, including a detecting cell and means for allowing the passage of substantially only that light having a wavelength substantially equal to the wavelength of light from said light source;
- and
- (d) means for measuring the temperature of said sample as said sample passes through said transition temperature.
A method for determining the phase transition temperature of a liquid hydrocarbon sample comprising simultaneously:
- (a) projecting a highly parallel beam of monochromatic visible light from a light source along an optical pathway in said liquid hydrocarbon sample;
- (b) measuring the temperature of the liquid hydrocarbon sample;
- (c) controlling the temperature of said liquid hydrocarbon sample to pass through the phase transition temperature of said sample;
- (d) substantially only that light having a wavelength substantially equal to the light from said source to exit said pathway;
- (e) detecting the intensity of the light exiting said optical pathway;
- and
- (f) analyzing the intensity of said detected light to determine the temperature at which the phase transition of the liquid hydrocarbon occurs.
Dependencies are inferred from the claim text.