Process and apparatus for investigating and controlling changes of state of a liquid or gelled medium by differential thermal analysis

摘要

Gelling of a liquid or liquefication of a gel are investigated or controlled by differential measurement of thermal characteristics of the involved medium. The temperature of the medium is measured by a first probe (delivering a first temperature indicating signal) while a second probe (sufficiently far away from the first probe not to disturb the latter through temperature changes) imparts heat to said medium and delivers a signal corresponding to its temperature. The signals respectively emitted by the probes are processed in an electrical data processing unit wherein the signals are combined in a correcting stage which corrects the signal delivered by the second probe taking into account the signal delivered by the first probe to deliver information indicating the change of state of the medium.