Three techniques were used to improve the measurement uncertainty of a commercial emissometer, which was manufactured by the Devices and Services Company. In order to mitigate the errors from ambient disturbance, the emissometer was put into a thermostat water bath, i.e. a heat sink, and wrapped with insulators. A data acquisition interface was added in the emissiometer system for the purpose of automatic data acquisition. This allows statistical data sampling and accurate analysis can be performed. A secondary standard meter was used to closely monitor both signals from the thermalpile and the output of the standard platinum resistance thermometer (SPRT). Thermal error due to the temperature difference between the water bath and ambient was thus reduced. These new amendments to the emissometer improve the expanded uncertainty of about 160%. A detailed analysis is included in this paper. Results from simulation confirmed that the enhanced thermal insulation forced the major heat current within the emissometer to drain from the heat sink through the electric connectors to the ambient. (c) 2007 Elsevier B.V. All rights reserved.