To accurately detect the moving state of secondary atomic ions at the time of targeted voltage application and the moving state of secondary atomic ions due to diffusion. An ion movement measuring device includes a test specimen and a detector. The test specimen has a first electrode, a second electrode, and an electrolyte disposed between them. The first electrode and the second electrode each have a layer of an identical element, and have the identical potential in a state where no voltage is applied from outside the test specimen. At least the first electrode contains second atoms being isotopes of first atoms at an abundance ratio higher than a natural abundance ratio of the second atoms, the first atoms being present at a highest natural abundance ratio in the element. The detector detects some of ions of the first atoms and the second atoms, which are discharged from the electrolyte.

To accurately detect the moving state of secondary atomic ions at the time of targeted voltage application and the moving state of secondary atomic ions due to diffusion. An ion movement measuring device includes a test specimen and a detector. The test specimen has a first electrode, a second electrode, and an electrolyte disposed between them. The first electrode and the second electrode each have a layer of an identical element, and have the identical potential in a state where no voltage is applied from outside the test specimen. At least the first electrode contains second atoms being isotopes of first atoms at an abundance ratio higher than a natural abundance ratio of the second atoms, the first atoms being present at a highest natural abundance ratio in the element. The detector detects some of ions of the first atoms and the second atoms, which are discharged from the electrolyte.

A ceramic planar sensor element having four contact surfaces and three vias, for example for a lambda sensor. Measures are provided for increasing the loadability of the sensor element in relation to mechanical stresses. The measures relate in particular to the arrangement of the vias and to the design of insulating layers in the interior of the sensor element.

A NOx sensor element includes: a first pump cell configured to adjust an oxygen concentration in a first measurement chamber; a diffusion resistance portion configured to adjust a diffusion rate of a measurement target gas introduced into the first measurement chamber; and a second pump cell in which a pump current corresponding to a NOx concentration in the measurement target gas after the adjustment of the oxygen concentration, flows. The first pump cell includes: a first solid electrolyte; an inner pump electrode containing a noble metal, and exposed to the first measurement chamber; and an outer pump electrode containing a noble metal, and disposed outside the first measurement chamber. The outer pump electrode contains not less than 22% by mass of a main component of the first solid electrolyte.

A limiting current-type gas sensor element including a plurality of stacked ceramic layers and configured to output a limiting current value which depends on a concentration of a specific gas in a gas to be measured when a certain voltage is applied. The gas sensor element includes a solid electrolyte member having oxygen ion conductivity; a heater that heats the solid electrolyte member; a measurement electrode and a reference electrode provided on the solid electrolyte member; a chamber facing the measurement electrode and into which the gas to be measured is introduced; a gas inlet located to a tip side of the chamber in a longitudinal direction; and a diffusion resistance part provided in the gas inlet. A heating center of the heater is located further to the tip side than an electrode center of the measurement electrode is.

A limiting current-type gas sensor element including a plurality of stacked ceramic layers and configured to output a limiting current value which depends on a concentration of a specific gas in a gas to be measured when a certain voltage is applied. The gas sensor element includes a solid electrolyte member having oxygen ion conductivity; a heater that heats the solid electrolyte member; a measurement electrode and a reference electrode provided on the solid electrolyte member; a chamber facing the measurement electrode and into which the gas to be measured is introduced; a gas inlet located to a tip side of the chamber in a longitudinal direction; and a diffusion resistance part provided in the gas inlet. A heating center of the heater is located further to the tip side than an electrode center of the measurement electrode is.

Provided is an electrode for electrochemical measurement for detecting or quantitatively determining a target substance, the electrode comprising: a complex supported on a surface of the electrode, wherein the complex is a complex comprising a probe for the target substance, a quantum dot which binds to the probe and is doped with nitrogen and sulfur, and a conductive polymer nanowire in which a metal nanoparticle is embedded.

Provided is an electrode for electrochemical measurement for detecting or quantitatively determining a target substance, the electrode comprising: a complex supported on a surface of the electrode, wherein the complex is a complex comprising a probe for the target substance, a quantum dot which binds to the probe and is doped with nitrogen and sulfur, and a conductive polymer nanowire in which a metal nanoparticle is embedded.

A sensor element includes an element body that contains a measurement-object gas flow section and a heat generation portion. The measurement-object gas flow section includes a main pump chamber, an auxiliary pump chamber, and a measurement chamber. A distance X1 in a left-right direction between a part of a first inner linear portion and a part of a second inner linear portion of the heat generation portion that overlap a main pump chamber projection region is equal to or more than ⅓ of a width Wp of the main pump chamber projection region in the left-right direction. A distance X2 in the left-right direction between a part of the first inner linear portion and a part of the second inner linear portion that overlap an auxiliary pump chamber projection region is equal to or more than 0.4 times the width Wp.

A sensor element for detecting a target gas to be measured in a measurement-object gas includes: an element body including an oxygen-ion-conductive solid electrolyte layer; and a protective layer covering at least a part of a surface of the element body. The protective layer includes a porous material that has a pore inside; and, in the pore in the protective layer, a ratio (Lt/Lf) of a pore length (Lt) in a thickness direction perpendicular to the surface of the element body to a pore length (Lf) in a surface direction perpendicular to the thickness direction is 0.6 to 0.9.