Patent ID: 8746078

Claim:
An internal battery-type field device for measuring a physical quantity of a fluid flowing in a pipe portion, comprising: a connecting portion that extends from the pipe portion; an equipment case that is connected to the connecting portion; an internal battery that is contained in the equipment case and supplies driving power to the internal battery-type field device; a battery case that holds the internal battery, the battery case having a first face, a second face that is a face opposite the first face, and a third face that is an outer peripheral face of the battery case which connects the first face with the second face; a first elastic member that exhibits an elastic force, interposed between the first face of the battery case and an inner wall of the equipment case; a second elastic member that exhibits an elastic force, interposed between the second face of the battery case and the inner wall of the equipment case; and a third elastic member that exhibits an elastic force, interposed between the third face of the battery case and the inner wall of the equipment case, wherein the first elastic member is a wave ring-shaped spring disposed on the first face of the battery case along a peripheral edge of the first face.