Abstract: A flowmeter having a seal structure for preventing an inner case structure from becoming complicated and making it possible to easily assemble an inner case with an outer case even if an inflow port has a large diameter. A seal member including a pair of sheet members each having a circular opening provided in a central part and a protruding ring formed along the outer peripheral edge of the opening in a protruding shape that projects outward is inserted between the inner peripheral surface of a body case of an outer case and the outer peripheral surface of an inner case. The protruding rings of the seal member are pressed by the inner peripheral surface of the body case of the outer case, seal the space between the outer case body part and the inner case, and prevent the leakage of fluid flowing through a flowmeter.

Abstract: A flowmeter having a seal structure for preventing an inner case structure from becoming complicated and making it possible to easily assemble an inner case with an outer case even if an inflow port has a large diameter. A seal member including a pair of sheet members each having a circular opening provided in a central part and a protruding ring formed along the outer peripheral edge of the opening in a protruding shape that projects outward is inserted between the inner peripheral surface of a body case of an outer case and the outer peripheral surface of an inner case. The protruding rings of the seal member are pressed by the inner peripheral surface of the body case of the outer case, seal the space between the outer case body part and the inner case, and prevent the leakage of fluid flowing through a flowmeter.