| 摘要 |
A broadband ultrasonic sensor for detecting ultrasound propagating through air from a source, within a broadband frequency range of detection, comprising a housing; a piezoelectric crystal with two sensitive surfaces and at least one outside surface between them, the piezoelectric crystal being arranged in the housing, all surfaces of the piezoelectric crystal are mechanically insulated from the housing, and the mechanical insulation is provided by a damping material holding the piezoelectric crystal that provides substantially free deformation of the piezoelectric crystal in response to characteristic ultrasound within a broadband frequency range of detection so that voltage is generated between the named two sensitive surfaces, the material impeding vibration of the piezoelectric crystal when it is subjected to vibrations located beyond the broadband frequency range of detection. Also proposed is a detector comprising the broadband ultrasonic sensor. |
