Optical sensorsOptical Sensors used for temperature measurements are very susceptible to errors when interfering with gaseous media are present in the optical path between the measured object and optical sensorOptical Sensors. These errors are not only of great magnitude but also random in nature, hence the use of optical sensorsOptical Sensors in real industrial scenarios like Flash FurnacesFlash furnace where interfering gaseous media are always present is increasingly challenging. This work proposes a correction to the two-color pyrometric technique for temperature estimation based on Planck’s radiation modelModel to correct errors in measured signal caused by the interfering medium. The basis of this correction method hinges on the fact that an effective emissivityEmissivity can be estimated by minimizing the error of the measured signal to the ideal object irradiance. Furthermore, an estimation of the transmission of the interfering medium can be estimated from the measured data, which is used to recover the original radiative signal of interest. This provides a low computational cost and effective method that estimates temperature accurately even in the presence of interfering media.