Testing irradiance and radiance methods for absolute radiation thermometry based on InGaAs detectors in the NIR at CEM/CSIC

After measuring thermodynamic temperatures in the range from 900 °C to 2500 °C, The Centro Espanol de Metrologia (CEM) in collaboration with the Instituto de Optica of the Consejo Superior de Investigaciones Cientificas (IO-CSIC) are currently involved in the measurement of thermodynamic temperatures down to 400 °C using radiometers based on InGaAs detectors with central wavelengths in the near-infrared spectral range (NIR). This communication summarizes the progress towards the extension of absolute radiation thermometry measurement range to lower temperatures.