偶看新闻四级听力新变化:智能手机下一代的标配系列3：气压表(Barometer)
来源：百度文库 编辑：偶看新闻 时间：2024/05/03 09:27:47
智能手机下一代的标配系列3：气压表(Barometer)
(2010-12-01 22:54:59)
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应用：
气压表也是一种压力传感器，新一代的气压表既可以测量气压和高度，又可以测量温度。所以它既可以做GPS的补充又可以预报天气，可以应用于户外活动和高空作业等，手机配置上这个功能无疑更加智能。
工作原理：
现在气压表只是一个2毫米见方的小芯片，当然不可能是基于托里拆利试验的水银气压计，而是基于piezo－resistive的压电传感器。石英SiO2等晶体,受到压力变化时导致电压的变化，从而电阻也会变化。
通过AD转换，输送到主机，即可知道压力的大小。而温度可以根据PVT的关系计算出来，你懂的。
名词解释 Piezo-resistive
Piezo is derived from the Greek word piezein, “to squeeze.”Piezoelectric materials
produce a voltage when strained. Piezoresistive materials exhibit achange in resistance
when subjected to pressure.
When pressure (stress) is applied to a material it creates astrain or deformation in the
material. In a piezoelectric material this strain creates anelectrical potential difference, a voltage. The effect isreversible. When an electric potential is applied across two sidesof
a piezoelectric material, it strains. Both effects were discoveredby Jacques and Pierre
Curie in 1880-1. The piezoelectric effect is found in materialswith a specific electical
crystalline structure. These are known as piezoelectricmaterials.