The present invention is in relation to a method and its apparatus, by means of which HCl generation formed from hydrolysis reactions or thermal decomposition of chloride salts is continuously monitored. Its application is in oil refining or in any other area where chloride salts are heated to temperatures high enough to cause hydrolysis reactions or thermal decomposition. The invention allows for a much more sophisticated and precise record of the thermal events that occur as a function of temperature. It also allows the behavior of chloride salts subjected to these conditions to be evaluated, both in model systems and in industrial saline solutions, with respect to the respective content, composition, or presence of components in the oil phase, such as carboxylic (naphthenic acids) or nitrogenous (ammonia or amines) acids.