空气负离子观测仪的封装结构设计及仿真

负离子浓度是衡量空气质量的重要指标。目前，多数空气负离子观测设备均针对室内测量或短时的室外测量设计，在室外长时间工作会受到风的影响，造成测量结果准确性降低。文章简要介绍空气负离子浓度观测仪的工作原理，分析了在室外工作情况下误差产生的原因，详细设计了不同的传感器封装结构，并通过流体力学计算方法进行仿真分析，比较了不同封装结构对测量结果的影响，最终得出T形封装外壳内部风场较均匀，更适用于室外长期观测设备封装的结论。

Design and Simulation of Package Structure for Negative Air Ion Observing Instrument

The number of negative air ions is one of important indexes of air quality. Most of the current observing instruments for negative air ions are designed and manufactured for indoor use or short time outdoor use. When applying these devices outdoors, some factors as wind will influence the observing results, leading to measurement accuracy decreasing. The principles of negative air ion observing instruments are introduced, and its deviations when used outdoors are analyzed. The different structures of the sensor package are designed, and their different impacts on sensors are compared through the computational hydro mechanical methods. The results indicate that the T type package has a more even wind field, and better for the packaging of outdoor instruments.