The techniques relate to methods and apparatus for conductance measurement. A device includes a fluid chamber, at least one sensor element configured to sense an analyte, wherein the at least one sensor element is in fluid communication with the fluid chamber, and a set of one or more electrodes in fluid communication with the fluid chamber for sensing a conductance of a fluid in the fluid chamber.

The techniques relate to methods and apparatus for conductance measurement. A device includes a fluid chamber, at least one sensor element configured to sense an analyte, wherein the at least one sensor element is in fluid communication with the fluid chamber, and a set of one or more electrodes in fluid communication with the fluid chamber for sensing a conductance of a fluid in the fluid chamber.

The method for calculating concentration ratio includes: (a) heating a gas sensor element to a temperature at which both of two gas components introduced in a gas sensor element react, and maintaining the temperature for a predetermined period to measure an electrical resistance value of the gas sensor element; (b) heating the gas sensor element to a temperature at which only any of the two gas components reacts, and maintaining the temperature for a predetermined period to measure an electrical resistance value of the gas sensor element; and (c) calculating a concentration ratio of the two gas components based on a combination of the electrical resistance value in (a) and the electrical resistance value in (b).

The method for calculating concentration ratio includes: (a) heating a gas sensor element to a temperature at which both of two gas components introduced in a gas sensor element react, and maintaining the temperature for a predetermined period to measure an electrical resistance value of the gas sensor element; (b) heating the gas sensor element to a temperature at which only any of the two gas components reacts, and maintaining the temperature for a predetermined period to measure an electrical resistance value of the gas sensor element; and (c) calculating a concentration ratio of the two gas components based on a combination of the electrical resistance value in (a) and the electrical resistance value in (b).

A gas sensor device includes: a first electrode; a second electrode; a metal oxide layer that is disposed between the first electrode and the second electrode and is in contact with the first electrode and the second electrode; an interlayer insulating film that covers a part of the first electrode, a part of the second electrode, and a part of the metal oxide layer; and a hydrogen permeable film that allows only hydrogen to permeate, a local region that is in contact with the second electrode is provided inside the metal oxide layer, the local region having a higher oxygen deficiency than an oxygen deficiency of the other region in the metal oxide layer, an opening that exposes a gas contact portion which is a part of a main surface of the second electrode is provided in the interlayer insulating film, and the hydrogen permeable film is provided to cover at least the gas contact portion.

An impedance measurement system for detecting an analyte in a sample is disclosed. The system includes first, second, and third electrodes, wherein at least a portion of the third electrode is positioned between the first and second electrodes, means for generating an electromagnetic field between the first and second electrodes, means for electrically controlling the third electrode, wherein the third electrode modifies the electromagnetic field, and a processor for detecting a presence of the analyte in the sample, based at least in part on a property of the electromagnetic field.

The disclosure provides a preparation method for a graphene material-based resistive gas sensor array and an application method thereof. The preparation method includes: adding a metal salt solution to a graphene oxide solution to obtain a mixed suspension, adjusting a pH of the mixed suspension and dispersing the mixed suspension under ultrasound, incubating the mixed suspension on a shaker, then washing it with deionized water followed by dispersing it in a deionized water to obtain metal ion-induced graphene oxide self-assembled suspension, and preparing a plurality of parts of the suspension by varying the preparation conditions; and adding the plurality of parts of metal ion-induced graphene oxide self-assembled suspension respectively to fingers of a multi-site interdigitated electrode array, and drying naturally, reducing the plurality of parts of the suspension at 60 to 120° C. for 3 to 30 min. The disclosure achieves uniform loading of a graphene material on a substrate.

Provided is a stress measurement system and a stress measurement method that are capable of measuring the stress level of a subject without taking time and effort. A stress measurement system 1 includes a sensor unit 31 that detects a plurality of detection target gases based on substances contained in a specimen of a subject and outputs a plurality of detection values corresponding to respective detection results of the plurality of detection target gases, and a control unit that determines a stress level of the subject, based on a combination of the plurality of detection values. In addition, the substances contained in the specimen may include a substance serving as a raw material for a brain neurotransmitter.

Provided is a stress measurement system and a stress measurement method that are capable of measuring the stress level of a subject without taking time and effort. A stress measurement system 1 includes a sensor unit 31 that detects a plurality of detection target gases based on substances contained in a specimen of a subject and outputs a plurality of detection values corresponding to respective detection results of the plurality of detection target gases, and a control unit that determines a stress level of the subject, based on a combination of the plurality of detection values. In addition, the substances contained in the specimen may include a substance serving as a raw material for a brain neurotransmitter.

A sulfidation detection sensor includes a rectangular parallelepiped insulating substrate, a resistor formed to adhere closely to a surface of the insulating substrate, a sulfidation detection conductor formed to adhere closely to a surface of the resistor, a protective layer that is impermeable to sulfide gas and formed to cover a portion of the sulfidation detection conductor, and a pair of electrode portions formed at both ends of the insulating substrate and connected to the resistor and the sulfidation detection conductor. The sulfidation detection conductor is made of metal having a resistance value less than that of the resistor, and includes an exposed portion exposed to the outside without being covered with the protective layer.