Design and experimental evaluation of a high-accuracy air temperature measurement instrument for meteorological...

High-accuracy surface air temperature measurements (typically within 0.05-0.1 °C) are essential for atmospheric research and climate science applications. However, such measurements are affected by multiple sources of uncertainty, including radiation-induced temperature deviations and sensor time response characteristics. To address these challenges, this study develops and experimentally evaluates a high-accuracy air temperature measurement instrument designed to minimize radiation-induced errors. The principal sources of measurement deviation-direct solar radiation, diffuse and reflected components, long-wave radiation, altitude-related air density, wind speed, and solar incident angle-are systematically analyzed. A novel instrument incorporating a streamlined air-guiding structure is proposed to enhance convective ventilation and reduce radiative heating. A computational fluid dynamics (CFD) model is established to quantify radiation-induced temperature deviations under various environmental conditions. Based on the CFD-generated dataset, a multilayer perceptron-based correction model is developed to perform multi-parameter nonlinear correction of radiation-induced temperature deviations. Comparative field experiments, conducted using a 076B fan-aspirated instrument as a reference, show that the proposed instrument achieves a root mean square error of 0.019 °C and a mean absolute error of 0.015 °C under the tested conditions. Radiation-induced temperature deviations are effectively constrained within 0.05 °C, indicating that the combined structural design and correction approach can significantly improve measurement accuracy.