The invention relates to devices for visually recording the fact of excess of temperature, namely to devices for recording the fact of excess of temperature above at least one threshold value, the operating principle of which is to change the
microstructure of a heat-sensitive material at given
threshold temperature values, accompanied by an irreversible visual effect, as well as variants of the method for manufacturing this device. The device for visually recording the excess of temperature above at least one threshold value, having a
layered structure including: —a base that is non-transparent to at least part of visible light, on the front surface of which inscriptions are applied indicating at least one numerical
threshold temperature value; —at least one temperature-sensitive material that is non-transparent to at least part of visible light, applied to individual sections of the base, the
microstructure of which includes particles of
solid organic substance and voids filled with the
gas phase; —a transparent protective layer that partially or completely covers the front surface of the device. In this case, the device is designed with the ability to irreversibly change its appearance upon reaching at least one
threshold temperature indicated on it due to the destruction of the
microstructure of the corresponding heat-sensitive material, accompanied by the fusion of particles of
solid organic substance, a decrease in the fraction of voids and an increase in its transparency with the development of the color of the base. Variants of a method for manufacturing the device for visually recording the excess of temperature above at least one threshold value are also disclosed. The group of inventions provides for an increase in the reliability and accuracy of visually recording the fact that the temperature has exceeded at least one threshold value, the impossibility of returning the heat-sensitive material to its original state, an increase in the
operating speed of the heat-sensitive material, including under conditions of short-term peak loads of controlled equipment elements or emergency operating
modes, as well as an increase in the safety of operation of both the controlled equipment and the recording device itself throughout its entire service life.