A non-invasive dry coupled disposable/reusable ultrasonic sensor has a housing and a piezoelectric element at one end of the housing to which connected signal leads are connected that extend out from the housing. A piece of double-sided adhesive tape has one adhesive side secured directly to the face at the one end of the housing with the other adhesive side to be secured directly to the outer surface of a pipe or vessel. The tape can cover the entire face of the one end of the housing or only that part that the piezoelectric element faces.