Abstract: A physical quantity measuring device includes: a cylindrical portion having therein an inner space; a first case provided to a first end of the cylindrical portion; a sensor unit housed in the first case; a second case provided to a second end of the cylindrical portion; a circuit portion housed in the second case; a heat insulating portion disposed to face the sensor unit; a sealing portion that defines a hermetic seal between the heat insulating portion and an inner circumferential surface of the cylindrical portion; a first partition member that separates the sensor unit from the inner space at the first end; and a heat-insulative second partition member that is in contact with an opening edge or the inner circumferential surface of the second end and separates the inner space from the circuit portion near the second end.

Abstract: A device includes: an outer case; an inner case; a cylindrical base having a distal end that penetrates through a cylinder of the outer case to be fixed to the outer case; and a fastener configured to be mounted on the distal end of the base, the fastener including: an exterior configured to be guided by a guide provided to the inner case; a fastener-side engaging portion engageable with the inner case; and a contact peripheral portion configured to be contact with the outer case to prevent the inner case from rotating relative to the outer case.

Abstract: A physical quantity measuring device includes: a cylindrical portion having therein an inner space; a first case provided to a first end of the cylindrical portion; a sensor unit housed in the first case; a second case provided to a second end of the cylindrical portion; a circuit portion housed in the second case; a heat insulating portion disposed to face the sensor unit; a sealing portion that defines a hermetic seal between the heat insulating portion and an inner circumferential surface of the cylindrical portion; a first partition member that separates the sensor unit from the inner space at the first end; and a heat-insulative second partition member that is in contact with an opening edge or the inner circumferential surface of the second end and separates the inner space from the circuit portion near the second end.

Abstract: A device includes: an outer case; an inner case; a cylindrical base having a distal end that penetrates through a cylinder of the outer case to be fixed to the outer case; and a fastener configured to be mounted on the distal end of the base, the fastener including: an exterior configured to be guided by a guide provided to the inner case; a fastener-side engaging portion engageable with the inner case; and a contact peripheral portion configured to be contact with the outer case to prevent the inner case from rotating relative to the outer case.