A sensor element includes: an element base made of an oxygen-ion conductive solid electrolyte; an internal space provided inside the element base; an electrochemical pump cell configured to pump oxygen in and out between the internal space and outside; a porous thermal shock resistant layer provided to an outermost peripheral part in a predetermined range at one end part of the element base, at which a gas inlet is provided; and a buffer layer adjacent to the thermal shock resistant layer on a pump surface and a heater surface. A thermal diffusion time in a thickness direction of the thermal shock resistant layer is 0.4 sec to 1.0 sec inclusive, and a total thermal diffusion time in a stacking direction of the thermal shock resistant layer and the buffer layer is 0.2 sec to 1.0 sec inclusive.

A sensor element includes an element base made of an oxygen-ion conductive solid electrolyte, an internal space provided inside the element base, an electrochemical pump cell that pumps oxygen in and out between the internal space and outside, and a porous thermal shock resistant layer provided to an outermost peripheral part in a predetermined range at one end part of the element base, at which a gas inlet is provided. A thermal diffusion time in a thickness direction of the thermal shock resistant layer is 0.4 sec to 1.0 sec inclusive. A thermal diffusion time at a leading end part of the thermal shock resistant layer covering the gas inlet at a farthest leading end position at the one end part is longest, and a thermal diffusion time at a pump surface is longer than a thermal diffusion time at a heater surface.

A gas sensor includes a sensing element having an electrode pad a metal terminal, and a separator that has insertion holes in which the metal terminal is held. The metal terminal includes a main body and an elastic portion that is integrally connected to the main body and is elastically connected to the electrode pad at a predetermined contact point. The main body includes a front-end-side restricting portion and a rear-end-side restricting portion that restrict the movement of the main body by contacting wall surfaces of the insertion hole when the main body moves in a direction intersecting the direction of an axial line. The contact point is located between the front-end-side restricting portion and the rear-end-side restricting portion in the direction of the axial line. The front-end-side restricting portion and the rear-end-side restricting portion are connected to each other so that a flat board portion is interposed therebetween.

A gas sensor includes a sensing element that includes an electrode pad, a metal terminal, and a separator. The metal terminal includes a lead-wire-connecting portion, a main body, a protruding piece that protrudes from a front-end side, and an elastic portion connected to an end of the protruding piece and to the electrode pad. An area S1 of a first opposed surface of a primary surface facing an insertion hole of the separator is larger than an area S2 of a second opposed surface of a secondary surface facing the insertion hole, and a part of the second opposed surface contacts an inner circumferential surface of the separator forming the insertion hole, and the first opposed surface is separated from the inner circumferential surface, where surfaces of the main body and the protruding piece that are located opposite the elastic portion are the primary surface and the secondary surface.

A metal terminal includes a front-side terminal member and a rear-side terminal member. The front-side terminal member includes a female connection portion, and the rear-side terminal member includes a male connection portion. The female connection portion has an insertion port in which the male connection portion is inserted. The insertion port is formed in a shape that prevents the insertion port and the male connection portion from coming into contact with each other when the male connection portion is inserted therein. The female connection portion includes a terminal contact portion which brings the male connection portion and the female connection portion into contact with each other by pressing the male connection portion toward the female connection portion inside the female connection portion.

An apparatus comprising a heating unit and a support device is disclosed which apparatus is designed to place a controlled amount of heat into a very localized area of a substrate of interest. The substrate of interest here is intended to be a portion of a large structure [such as the portion of a ship]. The heating unit comprises a heat source and the necessary structure to closely control the heat applied to the substrate of interest. The support device supports the heating unit directly over the substrate of interest and permits the system to be secured to one surface of the substrate of interest in a removable and non-destructive manner. The support device has legs which have securing means on the bottom thereof to secure the system to one surface of the substrate of interest in a releasable and non-destructible way.

A gas sensor includes a detection circuit unit that detects a specific gas component in measured gas based on output from a sensor element. The detection circuit unit includes an AC voltage application unit that applies an AC voltage signal to a pair of electrode units in an electrochemical cell, a gas concentration detection unit that detects concentration information on the specific gas component from a DC signal component included in an output signal provided by the electrochemical cell, and a cell temperature detection unit that detects temperature information on the electrochemical cell from an AC signal component included in the output signal. The cell temperature detection unit includes a signal extraction unit that removes the DC signal component to separate the AC signal component from the output signal, and a synchronous detection unit that performs synchronous detection on the separated AC signal component using the AC voltage signal.

The heater 72 of the heater portion includes the linear portions 78 and the bend portions 77. A resistance value per unit length of the bend portions 77 at least at a temperature within a temperature range of no less than 700° C. and no more than 900° C. is lower than a resistance value per unit length of the linear portions 78.

A sensor element includes: an element base including: a ceramic body made of an oxygen-ion conductive solid electrolyte, and having an inlet at one end portion thereof; at least one internal chamber located inside the ceramic body, and communicating with the gas inlet; and an electrochemical pump cell including an outer electrode, an inner electrode facing the chamber, and a solid electrolyte therebetween, and a porous leading-end protective layer covering a leading end surface and four side surfaces in a predetermined range of the element base on the one end portion, wherein the protective layer has an extension extending into the gas inlet and fixed to an inner wall surface of the ceramic body demarcating the gas inlet, and a gap communicating with the gas inlet is located in the protective layer, with demarcated by a portion of the protective layer continuous with the extension.

A gas sensor element for detecting a specific gas component in a measured gas, comprising: an element body in the form of a long plate having a gas detection part at an end thereof on a distal end face side in a longitudinal direction; and a porous protective layer covering an outer periphery of the end on said end face side of the element body, wherein in a cross section including two adjacent ones of the end face and side faces connected to the end face, an outer surface of the protective layer facing an element corner where the two faces meet has a shape with a corner part, and a ratio of an assumed diameter of a water droplet contained in the measured gas in a use environment to an effective length of the corner part in the cross section is equal to or larger than 1.5.