一种用于图书档案库的小波加权式声表面波温度传感器的关键问题研究

本文提出把声表面波温度传感器用于图书档案库的温度控制系统中.当图书档案库中温度变化时,该温度传感器的输出频率与温度成线性关系,从而达到测量温度的目的.同时还提出将输入换能器变迹加权函数、换能器的指条数对声表面波功率的影响作为两个关键问题进行了研究,并且解决了这两个关键问题.在声表面波温度传感器的研究中,用小波函数对输入换能器进行变迹加权,导致于抑制了该温度传感器频率特性曲线的旁瓣.换能器的指条数越多,产生的体声波越弱(即换能器的指条数越多,产生的声表面波越强).只要换能器的指条数大于40条时,产生的体声波可以忽略,而产生的声表面波是很强的.并且对该温度传感器的设计、制作及实验进行了详细研究.

Study of a Wavelet weighting Surface Acoustic Wave Temperature Sensor Applied in Library and Archives

We propose to apply the surface acoustic wave (SAW)temperature sensor in the temperature control system of library and archive.When the temperature of library and archive changes,the output frequency of the SAW temperature sen-sor is linear with the temperature,thus the temperature can be measured.We also present the trace weighted function of the in-put transducer,and the influence of transducer electrode-numbers on the SAW power as two key problems of the SAW temper-ature sensor.The solutions to these problems are achieved in this study.The wavelet function is used as the trace weighted function of the input transducer,so that the sidelobes for the frequency characteristic curve of the SAW temperature sensor are suppressed.The more the transducer electrode number are,the weaker the bulk acoustic wave (BAW)is (i.e.,the more the transducer electrode-numbers are,the stronger the SAW is).As long as transducer electrode numbers are more than 40,the ex-cited bulk acoustic wave (BAW)can be ignored,but the excited SAW is very strong.The design,fabrication and experiment for the SAW temperature sensor have been studied in detail.