To compare the humidity‑measurement performance of the three meteorological‑purpose humidity sensors and guarantee the accuracy and representativeness of comparison results, eight sensors of each aforementioned model are randomly selected from more than 130 verified sensors. The humidity‑verification system of the Xingtai Meteorological Verification Laboratory serves as the experimental setup. This work provides theoretical references for measurement‑accuracy analysis and humidity correction.
The results show that in terms of expanded uncertainty U, the relationship follows U_{\text{DHC1}}>U_{\text{DHC2}}>U_{\text{HMP155}}. The HMP155 sensor outperforms DHC2, which in turn outperforms DHC1. The expanded‑uncertainty values of DHC2 and HMP155 are relatively close. Comparing combined‑standard‑uncertainty U_c values across each verification point, the HMP155 sensor exhibits favorable consistency of combined‑uncertainty values at all verification points. Consistency ranks as HMP155 > DHC2 > DHC1.
Based on humidity‑verification data obtained from eight randomly‑selected sensors of each of the three models (HMP155, DHC2 and DHC1) among over 130 sensors tested in 2025, classification and statistical processing are carried out to ensure accurate and representative comparison findings. Type‑A and Type‑B uncertainty evaluations are conducted for each sensor model; standard uncertainty, combined standard uncertainty and expanded uncertainty are subsequently computed.
For expanded uncertainty U, U_{\text{DHC1}}>U_{\text{DHC2}}>U_{\text{HMP155}}. HMP155 performs better than DHC2, and DHC2 performs better than DHC1. The expanded‑uncertainty values of DHC2 and HMP155 are quite similar. Literature review indicates that DHC2 and HMP155 share similar working principles, which differ from those of core components in the DHC1 sensor.
From combined‑uncertainty values at respective verification points, the DHC1 model presents poor consistency, whereas the HMP155 sensor achieves good consistency of combined‑uncertainty values across all verification points. Performance consistency ranks HMP155 > DHC2 > DHC1.
This paper analyzes and obtains expanded uncertainty for verification results of three commonly‑used humidity sensors for automatic weather stations. The conclusions apply only to results of the present experiment. The evaluation method adopted offers references for uncertainty assessment of humidity‑sensor verification. It bears practical value for enhancing the reliability of humidity‑verification results and improving data accuracy. It supplies supporting data for selecting appropriate sensor models in practical operations or implementing targeted error correction for different models, and provides theoretical references for measurement‑accuracy analysis and humidity correction.