Sensitivity is the key in process of successful detection on yarn tension using SAW yarn tension sensor.By studying relationship between sensitivity of SAW yarn tension sensor and substrate strain rate of SAW yarn tension sensor

propose a theory

which can improve sensor sensitivity through increasing substrate strain rate.Based on the theory

a scheme is given to obtain the optimal substrate strain rate through flexibly design substrate size. In order to obtain substrate size corresponding to the optimal substrate strain rate

mathematical model between substrate strain rate and substrate size is established; a linear programming model is proposed to solve the substrate size corresponding to the maximum substrate strain rate

that is the substrate size corresponding to the optimal sensitivity. Experimental results confirm that the method can significantly increase SAW yarn tension sensor sensitivity up to 3 132. 4 Hz / gf.