A bearing device for bearing a shaft having a bearing, a supporting structure for supporting the bearing and at least on piezoresistive sensor incorporated in the supporting structure in an integrated manner which is arranged in the flux region of the bearing apparatus is provided. New electrolytes have been found that increase positive and negative polarity analyte ion signal measured in ESMS analysis when compared with analyte ESMS signal achieved using more conventional electrolytes. Thus, in a resin molding process using a seal sheet, the land electrode is forced into, and strongly adhered to, the seal sheet when pressure is applied through dies, and no resin encapsulant reaches the land electrode.