The present invention describes the fabrication of a small electrically isolated temperature microsensor. The device is presented with two distinct configurations. For the first configuration the thermocouple is fabricated in the interior of a silica capillary by applying electric discharges in the region where the butt contact of the two metallic wires occurs. The second configuration enables the pre-fabrication of the thermocouple, using the technique of adjacent contact of the two metallic wires before it is inserted into a silica structure containing two or more ports, for example a twin hole-fibre. The end containing the thermocouple junction is subsequently sealed by applying heat by means of a flame or an electric discharge, for example.

After the calibration of the respective thermocouple and subsequent treatment of the data relating to the heat transfers in the system, the configurations that have been presented are capable of measuring temperature in small systems and in systems with a high temperature gradient, for example, temperature measuring in samples submitted to electric discharge.