We are developing a system to convert infrared into visible radiation, employing β-diketonate chelate europium (III) thenoyltrifluoroacetonate (EuTTA) as the active medium of conversion. The operational principle of the proposed device is based on the variation of EuTTA fluorescence spectral power and lifetime with temperature. Previously, we characterized the fluorescence properties of the EuTTA in order to achieve IR-to-visible conversion and presented the work performed in order to calibrate our experimental setup. The results showed that a relation between the temperature variations of EuTTA film and those of the impinging IR radiation could be established. However, experimental data exhibited sufficient noise to cause significant errors between the measured and the actual temperature. In this work, we apply a filtering analysis using Fourier theory in order reduce the error in the data, increasing the resolution of our system. After the filtering, the standard deviation in the calculation of fluorescence parameters was reduced and therefore the thermal resolution of our system improved to 0.07 K.