Abstract: A failure prediction system for performing failure prediction to a monitoring target device by detecting a state, comprising: a state detection unit for detecting state signals of no smaller than two different kinds, and outputting a detection signal corresponding to each of the state signals; a phase processing part for synchronizing a plurality of the detection signals; a signal analysis part for calculating a feature value indicating a feature of the state for each of the detection signals from the phase processing part; and a failure prediction part for performing failure prediction of the monitoring target device for each of the feature values by comparing the feature value in question and a reference value set in advance.

Abstract: Acceleration sensor comprises vibrating element including piezoelectric body, circuit board amplifying output charge of the piezoelectric body that is generated due to bending vibration of the vibrating element, and sensor housing composed of highly conductive material, the sensor housing loading the vibrating element and the circuit board. The circuit board includes one or two extending region(s) formed so as to protrude from one side of the circuit board, the extending region(s) connecting mechanically and electrically the circuit board to the vibrating element. The sensor housing includes supporting base supporting the vibrating element, and recess portion is formed on the supporting base. The supporting base is configured such that the extending region(s) of the circuit board cover(s) the recess portion, and the vibrating element is fixed and supported by insulating adhesive agent with which space that is formed from the recess portion and the extending region(s) is filled.