Study of the Spectral Responsivity for the 900 nm Centered Filter Radiometer

The spectral responsivity of the filter radiometer（FR）is an essential parameter which needs to be measured accurately in the radiometric determination of the thermodynamic temperature. In this paper the facility of the spectral responsivity measurement and a 900 nm centered FR are studied. The influence issues of the facility and the FR, including the central region, wings and the wavelength step, are discussed. The measurement repeatability of the integration of spectral responsivity is estimated 0.03%, which is suitable for the requirement.