A synthetic phased array surface acoustic wave sensor to quantify bolt tension and a method for determining or estimating the tension in bolts using surface acoustic waves. In a preferred embodiment, coil temperature is calculated at the beginning of each long seek. A basis is determined from the tester information to be used for plotting the data clusters. While the implant mask is in place, dopant is implanted into the uncovered second portion of the capacitor channel region location. The inductive device is coupled with the switch.