Sometimes after tightening, due to bending of the bolt, this position may move. The position of the transducer should be changed to the location on the bolt that provides the maximum return echo signal. This assures the optimum sound path is being used, both before and after tightening. In non-magnetic bolt materials, fixtures are sometimes used to hold the transducer in place. Transducer Selection Basic to the operation of the BoltMike SMII is the ultrasonic transducer.
Transducers vary in center frequency, diameter, and damping.
In the case of a difficult fastener, transducer selection becomes more critical. The best way to evaluate an application is to use the BoltMike SMII waveform display. Try making readings with an assortment of transducers and observe the waveform display and the stability of the reading. Pick a transducer that provides a large signal and stable, repeatable readings when removing and replacing the transducer. The frequency of a transducer refers to the resonant frequency of the piezoelectric crystal.