Abstract: The present invention relates to an apparatus and process for estimating the pour point of a hydrocarbon oil. The pour point of hydrocarbon oil gives an indication of its low temperature properties, and is determined according to the time-consuming procedures set out in the American Society of Testing and Materials (ASTM) test D-97. The present invention generally provides a convenient means to estimate the pour point of a hydrocarbon oil, by directing a flow of pressurized gas towards a sample of the oil, and determining the warmest temperature at which the gas flow does not cause a substantial surface wave on the oil surface.

Abstract: Apparatus for monitoring the cloud point of a liquid, or the temperature at which any light scattering phase occurs therein, comprising a light-proof and light-absorbing chamber, and a liquid sample-receiving receptacle within the chamber having a bottom formed by a non-light-scattering surface; this surface being in thermal contact with a heating or cooling device, such as a thermoelectric cooler, and with a temperature measurement device. The chamber can be opened to allow access to the receptacle so that sample liquid can be placed therein. A light beam source is located to direct a beam of light onto the surface at an incident angle so that light from the beam is reflected or absorbed by the surface. A light detector including a lens and an array of detection cells is arranged so as to detect scattered light which is produced when solid material forms in the liquid as it is cooled or disappears on heating.