Determining the temperature at which a substance changes state
OwnerBizhan Rahimzadehinventor
Life of this patent
Estimating the term…
Abstract
Infra-red light from an emitter is directed through a glass slide to an area on which a solid substance is located. Light reflected from the undersurface of the solid substance is received by a receiver. The substance is heated by a strip heater. When the substance changes state, the amount of reflected light arriving at the receiver varies, and information coming from an electronic thermometer records the temperature at which the change of state has occurred.
Claims16
A method of determining the temperature at which a substance changes state comprising impinging a light beam on a region of the back side surface of a substance, directly heating said back side of said substance to at least its melting point with means which does not interfere with said impinging light beam or a reflection thereof from said back side surface, monitoring a change in light reflected from the back side surface of the substance when the substance undergoes at least a partial change in state as a function of the temperature of said surface, and measuring the temperature at which the substance changes state, said change of state being indicated by said change in light reflectance.
Monitoring apparatus for determining the temperature at which the surface of a substance changes state comprising:
- a substance, whose state is to be determined, disposed in a test region in a position such that a back side surface thereof is substantially downwardly directed;
- means for emitting light spaced from said substance and located and positioned to impinge light emitted therefrom against said downwardly directed back side surface of said substance, said light being reflected therefrom;
- means for directly heating at least a region of said downwardly directed back side surface of said substance to at least a temperature at which said region changes state, which heating means does not interfere with light emitted or reflected thereof;
- means for measuring the temperature at which said back side surface of said substance changes state;
- and
- means, disposed below said downwardly directed back side surface, for determining a change in said reflected light indicative of said change of state.
Dependencies are inferred from the claim text.