Evaluation of measurement uncertainty of HMP155A humidity sensor based on correlation analysis of input quantities

Abstract In view of the current situation that when the humidity sensor used GUM to evaluate the measurement uncertainty, the correlation between the input quantities was not analyzed. We taked the measurement result of the HMP155A humidity sensor at 55% RH as the research object, and analyzed the correlation of its input quantities. After compatibility judgment and calculation of correlation coefficients, the correlation degree was quantified. The evaluation results show that the extended uncertainty of the forward and reverse stroke are both 1.2%RH. The research results show that the measurement uncertainty deviated when the correlation between input quantities was not analyzed, which can easily lead to errors in the determination of instrument conformity. Using this method can effectively make up for the lack of correlation analysised in GUM’s evaluation of humidity sensors in the past, the evaluation content is closer to reality, and the evaluation results are more true and reliable.