Abstract: A gas sensor (1) including a sensor element (10); a metallic shell (138); a tubular outer surface member (190) attached directly or indirectly to the metallic shell, constitutes an outer surface of the gas sensor, and extends toward a rear end side in relation to the metallic shell; and a tubular protection member (210, 220) which is detachably fixed to a fixation region C1, C2 of an outer circumference of the outer surface member. The protection member includes a first arc portion (212), a second arc portion (222), and a fixation portion (214,224) brought into contact with and is fixed to the fixation region. When the protection member fixed to the outer circumference of the outer surface member by fixing the fixation portion to the fixation region is viewed in the axial O direction, the first arc portion and the second arc portion cover in total at least 90% of the entire circumference of the outer surface of the outer surface member.

Abstract: A gas sensor (1) including: a sensor element (21) having an electrode pad (24); a metal terminal (75) electrically connected to the electrode pad via a contact portion C1; and a separator (91) retaining the metal terminal, wherein the metal terminal includes a stopper portion (75p) extending in a direction crossing the axial-line 0 direction, and where, in a pair of one of an electrode pad (241) and one of a metal terminal (751) connected thereto, as seen along a widthwise direction of the sensor element, an end of the one electrode pad that is closest to one inner surface 91si of the separator is defined as a pad end, a distance between the pad end and the contact portion is defined as DA, and a distance between the one inner surface of the separator and a distal end of the stopper portion is defined as DB, DA>DB is satisfied.

Abstract: A sensor (1) comprising: a sensor element (10); metal terminals; and a front side separator (90) and a rear side separator (95) to hold the metal terminals, the metal terminals each include a front side metal terminal (30) and a rear side metal terminal (40) respectively held by the front side separator and the rear side separator, a first connection portion (33) is provided on a rear side of the front side metal terminal, a second connection portion (43) is provided on a front side of the rear side metal terminal, and an axis P2 of one of the first and the second connection portion, in all of the plurality of metal terminals, is displaced toward a radially outer side of the sensor element relative to an axis P1 of a counterpart thereof, and the first connection portion and the second connection portion are in contact with each other.

Abstract: A gas sensor (1) including a sensor element (10) and a separator (90) having an element hole (90 h), as viewed from one of a forward-end or a rear-end side in the axial direction. The separator has end surfaces (90 e) located axially farthest toward the one of the forward-end or the rear-end side, recess regions (90 h), (90 r 1) and (90 r 2) recessed from the end surfaces, and regions R1 and R2. First regions R1 are determined by eliminating a region SB occupied by the sensor element from a region SA defined by imaginary short-side lines and the outer edge of the separator. Second regions R2 are determined by eliminating the region SB from a region SC defined by imaginary long-side lines and the outer edge of the separator. S2/S1?0.5 is satisfied, where S1 is the total area of R1 and R2, and S2 is the total area of the recess regions.

Abstract: A sensor (1) comprising: a sensor element (10); metal terminals; and a front side separator (90) and a rear side separator (95) to hold the metal terminals, the metal terminals each include a front side metal terminal (30) and a rear side metal terminal (40) respectively held by the front side separator and the rear side separator, a first connection portion (33) is provided on a rear side of the front side metal terminal, a second connection portion (43) is provided on a front side of the rear side metal terminal, and an axis P2 of one of the first and the second connection portion, in all of the plurality of metal terminals, is displaced toward a radially outer side of the sensor element relative to an axis P1 of a counterpart thereof, and the first connection portion and the second connection portion are in contact with each other.

Abstract: A gas sensor (1) including a sensor element (10) and a separator (90) having an element hole (90h), as viewed from a particular side which is a forward-end side or a rear-end side. The separator has end surfaces (90e) located farthest in an axial direction toward the particular side, recess regions (90h), (90r1) and (90r2) recessed from the end surfaces, and first regions R1 and second regions R2. First regions R1 are determined by eliminating a region SB occupied by the sensor element from a region SA defined by imaginary short-side lines and the outer edge of the separator. Second regions R2 are determined by eliminating the region SB from a region SC defined by imaginary long-side lines and the outer edge of the separator. A relation of S2/S1?0.5 is satisfied, where S1 is the total area of R1 and R2, and S2 is the total area of the recess regions.