科学素养与生活应用·英语30篇（2）

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气象站湿度传感器如何非接触式测量水蒸气含量

Capacitive humidity sensors use polymer films whose dielectric constant changes with absorbed moisture.
As ambient humidity rises, water molecules penetrate the film and alter its electrical capacitance.
This change is measured precisely by an oscillator circuit whose frequency shifts proportionally.
Resistive sensors rely on hygroscopic salts whose conductivity increases with water absorption.
Both types avoid moving parts, ensuring long-term stability in outdoor installations.
Calibration against chilled-mirror dew point meters ensures traceable accuracy within ±2% RH.
Temperature compensation circuits correct for thermal drift during rapid weather transitions.
Wireless stations transmit raw sensor data to central servers for real-time map generation.
High-resolution networks now detect microclimates near forests, rivers, or urban heat islands.
These measurements directly feed drought forecasting models and wildfire risk assessments.