说明：  空气湿度报警器，顾名思义，是用来测量空气中的湿度的仪器，他通过一个湿敏电容和一个频率输出电路对空气湿度进行检测，把湿度变化转变成频率输出。再通过单片机把输入的频率转化为湿度百分值并通过LCD显示出来，使人可以通过显示清楚地看到空气的相对湿度。在单片机编程时可以预先设定一个限定值，当环境湿度达到设定的湿度值时电路报警，同时发光二极管变亮，达到湿度报警的目的。
(Air humidity alarm, as the name implies, is used to measure humidity in the air apparatus, he humidity through a capacitor and a frequency output circuit for detection of air humidity, the humidity changes in the frequency of the output into. Through the single-chip frequency of the input into a percentile and humidity through the LCD display, one can clearly see through the display of the relative humidity of air. Single-chip can be programmed in advance to set a limit value, when the environmental humidity to achieve set alarm circuit humidity values, while LED light changes to achieve the purpose of humidity alarm.)