湿度、温度和洁净度是影响空气质量的三大因素。湿度的高低不但直接关系到人们的生活质量 ,还严重影响到工农业生产的正常运行。现实生活中 ,当空气相对湿度超过 40 %时 ,钢铁腐蚀现象就会发生 ;当相对湿度超过 70 %时 ,人们常常感到湿热难耐 ;当相对湿度为5 0 %时 ,绝缘材料的 Humidity, temperature and cleanliness are the three major factors affecting air quality. The level of humidity not only directly affects people’s quality of life, but also seriously affects the normal operation of industrial and agricultural production. In real life, when the relative humidity of the air exceeds 40%, corrosion of steel occurs; when the relative humidity exceeds 70%, people often feel uncomfortable; when the relative humidity is 50%, the insulation material