A gas sensor, which includes a solid electrolyte layer including positive charge carriers to which detection-target gas coordinates, an electrode arranged on part of a plane of the solid electrolyte layer, and a unit configured to accelerate movements of the positive charge carriers.

A sensor device is for detecting metal. The sensor device may have a substrate, an electrode on the substrate, and a biopolymer-metal composite film on the electrode. The biopolymer-metal composite film may include a metal and a biopolymer. The sensor device may further have circuitry coupled to the electrode and configured to apply a sensing signal to the electrode.

A controller of a gas sensor includes: a concentration identification part identifying a concentration of a predetermined gas component based on a measurement pump current flowing between a measurement electrode and an out-of-space pump electrode in accordance with the concentration of the predetermined gas component due to application of a predetermined pump voltage; and a correction processing part correcting the concentration of the predetermined gas component identified by the concentration identification part, the correction processing part corrects the concentration of the predetermined gas component based on a correlation identified in advance between an offset current value as a magnitude of the measurement pump current when a measurement gas not containing the predetermined gas component flows or a normalized value of the offset current value and output fluctuations of the measurement pump current at startup of the gas sensor.

An inspection apparatus for electrical inspection of a substrate is provided. The inspection apparatus includes: a probe card including a plurality of probes; a stage on which the substrate is placed, the stage being configured to move the substrate relative to the probe card and to bring the substrate into contact with the probes; and a controller configured to control a movement of the stage. The controller calculates, using a first displacement amount based on a vertical load of the probe card and a second displacement amount based on an unbalanced load of the probe card that is inclined with respect to the vertical load, a three-dimensional correction amount for the unbalanced load of the probe card, and the controller moves the stage based on the three-dimensional correction amount.

The control section of a control apparatus executes a first control for operating a voltage application section such as to cause a current to flow in a first direction through a gas sensor in a first period, and a second control for operating the voltage application section such as to cause a current to flow in a second direction, opposite to the first direction, through the gas sensor in a second period. The control apparatus changes the length of at least one of the first period and the second period based on a comparison between a first measurement value, which is the absolute value of a value measured by a sweep measurement section during execution of the first control, and a second measurement value, which is the absolute value of a value measured by the sweep measurement section during execution of the second control.

A method for ascertaining an internal resistance of a sensor element. The method includes: ascertaining a reference voltage between a first electrode and a second electrode; impressing of a first current pulse having a first current by a pulse-generating unit at a first time; ascertaining at least two voltage values at two different times after an elapsing of a first settling time after the first time; ending the first current pulse and impressing an opposite second current pulse having a second current at a second time, ending the second current pulse at a third time; ascertaining a linear equation as a function of the at least two voltage values and the times; extrapolating a voltage value at the first time using the linear equation; ascertaining an internal resistance of the sensor element as a function of the extrapolated voltage value, the reference voltage, and the first current.

A gas sensor includes a sensor element body having a porous layer provided on an outer surface, and a power supply device which supplies power to a heater element that is in the sensor element body. The amount of power being applied to the heater element by the power supply device when gas detection is being performed by the gas sensor in a steady state is designated as P [W], the volume of the length range of a heating region of the heater element provided in the sensor element body as V [mm.sup.3], and the applied power density as X [W/mm.sup.3], where X is a value expressed by P/V. In that case, the following relationship is satisfied between the applied power density X and the average thickness Y [μm] of the porous layer:

Y≥509.32−2884.89X+5014.12X.sup.2

A gas concentration measurement system includes a limiting current-type gas sensor, a voltage source connected to the limiting current-type gas sensor, a current detector connected to the limiting current-type gas sensor, and a gas concentration arithmetic unit connected to the current detector. The voltage source supplies first and second voltages to the limiting current-type gas sensor. The first and second voltages generate first and second limiting currents corresponding to first and second gases, respectively, in the limiting current-type gas sensor. The current detector acquires first and second limiting current values of the limiting current-type gas sensor when the first and second voltages are applied to the limiting current-type gas sensor, respectively. The gas concentration arithmetic unit includes a difference acquiring section that acquires a difference between the second and first limiting current values and a gas concentration acquiring section that obtains concentration of the second gas based on the difference.

A gas sensor includes a sensor element including an element body, a first electrode, a second electrode, and a heater; a voltage acquisition section that acquires a voltage between the first electrode and the second electrode; a heater power supply; an external common lead that serves as both at least part of an electric circuit used to acquire the voltage by providing electrical continuity between the first electrode and the voltage acquisition section and at least part of an electric circuit used to supply an electric power from the heater power supply to the heater and that is disposed outside the sensor element; and a correction section that derives a value of a voltage drop in the external common lead in accordance with a heater current and that corrects the voltage acquired by the voltage acquisition section in accordance with the derived value of the voltage drop.

An electrochemical gas detector includes an electrochemical cell, a switching circuit, and a drive circuit. The switching circuit is electrically coupled to the electrochemical cell and to the switching circuit. The drive circuit includes a working-electrode terminal, a counter-electrode terminal, and a reference-electrode terminal. The electrochemical cell includes a first electrode, a second electrode, and a third electrode. The switching circuit has a first state in which the first electrode is electrically coupled to the working-electrode terminal, the second electrode is electrically coupled to the counter-electrode terminal, and the third electrode is electrically coupled to the reference-electrode terminal. The switching circuit has a second state in which the first electrode is electrically coupled to the counter-electrode terminal, the second electrode is electrically coupled to the working-electrode terminal, and the third electrode is electrically coupled to the reference-electrode terminal. A second drive circuit can be electrically coupled to the switching circuit.