Estimation of mixing ratios of two mixture solutions using shear horizontal surface acoustic wave (SH-SAW) sensors

Recently, surface acoustic waves sensors are developed and used in many applications. Estimation of the mixed electrolytes is one of these applications. This is done by using a flow of this solution passed between two interdigital transducers of SAW sensor. A certain kind of SAW will be generated and called shear horizontal (SH-SAW). This wave is very sensitive to these solutions, where clear perturbations in the attenuation and the frequency shifts of the received signal are observed. Experimental results of the flow liquid system with SH-SAW sensor are taken. From this data, an algorithm is proposed with the aid of backpropagation neural network that will be used directly to identify the two components of ions and determine the mixing ratio between the electrolytes. The durations of the time responses, fast Fourier transform (FFT), discrete cosine transform (DCT) are used as features in this algorithm.