Capacitor sensor

摘要

A condenser sensor ( 10 ) comprises an electrically conductive case ( 20 ) having an opening portion ( 22 a) formed therein and an opposing portion ( 22 b) opposing to and spaced apart from the opening portion ( 22 a); a fixed electrode ( 30 ) received in the electrically conductive case ( 20 ) through the opening portion ( 22 a); an electrically conductive diaphragm ( 51 ) accommodated in the electrically conductive case ( 20 ), the electrically conductive diaphragm ( 51 ) spaced apart from the fixed electrode ( 30 ) and opposing to the opening portion ( 22 a); an electrically conductive diaphragm supporting member ( 52 ) disposed in the electrically conductive case ( 20 ) to support the diaphragm ( 51 ); a circuit packaging board ( 60 ) disposed in the electrically conductive case ( 20 ) to be held in electrical contact with the fixed electrode ( 30 ) and the diaphragm ( 51 ) respectively through the electrically conductive case ( 20 ) and the diaphragm supporting member ( 52 ); and deformation protecting member ( 32 ) for protecting the opposing portion ( 22 b) from being deformed, in which the deformation protecting member ( 32 ) intervenes between the electrically conductive case ( 20 ) and the diaphragm ( 51 ), the deformation protecting member ( 32 ) is disposed inwardly of the circumference ( 51 b) of an oscillatable portion ( 51 a) of the diaphragm ( 51 ).