摘要 |
PURPOSE:To detect a chemical material with a high precision by constituting a detector so that its response is not dependent upon external circuits and avoiding the degradation of the detection precision due to the variance in characteristic of external circuits. CONSTITUTION:The detector consists of a piezoelectric substrate 13, which is formed by sticking an organic thin film 14 onto a surface acoustic wave(SAW) propagation path provided with an input electrode 11 and an output electrode 12, and a signal source 15. The organic thin film 14 selectively adsorbs a specific chemical material to be detected and its mass is changed before and after adsorption. By this SAW delay line constitution, the change of the mass of the organic thin film 14 due to adsorption of the chemical material is detected by frequency measurement. Since the frequency change is not dependent upon external circuits at all, it is not dependent upon characteristics of external circuits at all. Thus, the specific chemical material is detected with a high precision. |