Abstract: The present invention has as its object the provision of a controlled potential electrolysis gas sensor capable of speedily obtaining a state in which gas concentration measurement can be conducted after the activation of a power source. The controlled potential electrolysis gas sensor is configured to include at least a working electrode and a counter electrode which are provided in contact with an electrolytic solution and to detect a concentration of a detection target gas in a gas to be tested by detecting a current flowing between the working electrode and the counter electrode in a state in which the working electrode is controlled at a constant set potential. The controlled potential electrolysis gas sensor includes an operation control circuit that drives the controlled potential electrolysis gas sensor based on a current in a forward direction detected when the controlled potential electrolysis gas sensor is activated under energization conditions at the time of a gas detection operation.

Abstract: It is an object of the present invention to provide a calorific value measuring device and a calorific value measuring method which enable highly reliable measurement of the calorific value of a by-product gas produced in a steelmaking process. In the present invention, with a by-product gas produced in a steelmaking process being employed as an object gas of which calorific value is to be measured, the refractive index and the sonic speed of the by-product gas are measured so as to compute a refractive index equivalent calorific value QO from the value of the refractive index as well as a sonic speed equivalent calorific value QS from the value of the sonic speed. On the basis of the concentration XCO of carbon monoxide gas contained in the by-product gas, an error calorific value QCO is computed by Equation (1) below using a value selected within a range of ?0.08 to ?0.03 as a calorific value equivalent coefficient ?.

Abstract: Provided are a gas detection method and a gas detector which have a high durability to silicone poisoning and is capable of detecting the type and the concentration of a target gas to be detected with certain accuracy even when the detector is used in an environment where a silicone compound exists. The gas detector employs a contact combustion-type gas sensor which includes two gas detection elements, each intermittently driven, and in which only one gas detection element is supplied with a gas through a silicone removal filter. Acquired in an energization duration of each of the gas detection elements are two or more pieces of output data by the one gas detection element and two or more pieces of output data by the other gas detection element, which constitutes output variation patterns for a test gas.

Abstract: Disclosed is a gas sensor having high detection sensitivity, capable of detecting a gas at a low concentration and achieving lower power consumption. In the gas sensor including a gas detection element disposed on a thin-film insulator layer, the gas detection element includes: a heater layer provided on the thin-film insulator layer; and a gas detection layer having a thin-film thermistor part and an electrode part in contact with the thin-film, thermistor part, the gas detection layer being provided on the heater layer so as to be electrically insulated from the heater layer. The gas sensor is configured to detect a temperature change due to contact of a gas with the gas detection element on the basis of a change in resistance value in the thin-film thermistor part. The thin-film thermistor part preferably comprises a composite metal oxide containing Fe2O3, TiO2 and MgO.

Abstract: The present invention has as its object the provision of a methane number calculation method that allows for readily acquiring a methane number of a natural gas, which is a sample gas to be measured, with acceptable reliability irrespective of toe gas composition, and as another object the provision of a methane number measurement device that is capable of monitoring the fuel property of a natural gas to be used as a fuel gas.

Abstract: A method for measuring specific gravity of a combustible gas includes measuring the refractive index and sound speed of a gas of interest which contains at least one type of gas selected from a hydrocarbon gas, hydrogen gas, and carbon monoxide gas, and computing the value of the specific gravity Da of the gas of interest from Equation (1) below using a value selected as a correction factor x from within a range of 2.4 to 9.3 on the basis of a refractive index converted specific gravity Dn determined from the refractive index and a sound speed converted specific gravity Ds determined from the sound speed: Da=Ds?[(Ds?Dn)/(1?x)]??Equation (1).

Abstract: Provided is an explosion-proof structure of a power source part, an explosion-proof type battery unit and an explosion-proof type gas alarm, in which the degree of temperature rise upon short circuit of a secondary battery is reduced and explosion-proof performance with high reliability is achieved. The explosion-proof structure of a power source in an explosion-proof type apparatus employing a secondary battery as a power source for driving is fabricated by arranging a heat-radiating member composed of a metal at an outer peripheral surface of the secondary battery in a state that at least a part thereof comes into close contact with the surface. The explosion-proof type battery unit is composed of a cylindrical secondary battery and a heat-radiating member composed of a metal provided at an outer peripheral surface of the secondary battery in a state that at least a part thereof comes into close contact with the surface.

Abstract: Disclosed is a small-sized joint for joining hydrogen gas running route-forming members, which can surely prevent the leakage of hydrogen gas, and a portable hydrogen flame ionization gas detector that can prevent the leakage of hydrogen gas to achieve high safety. The joint comprises a metallic base having an internal space at least one end of which is opened, and a ring-like sealing member composed of an elastic material and arranged at opening edge of the metallic base, wherein a hydrogen gas running route-forming member is fixed in a state inserted into an internal space of the metallic base through the sealing member, and the sealing member is squeezed to gastightly seal the space, whereby one hydrogen gas running route-forming member is removably joined. In the gas detector, the joint is used to form a hydrogen gas running route.

Abstract: A contact combustion-type gas sensor that can maintain its initial sensitivity over a long period of time in the presence of silicon vapor, wherein an induction portion 5 of a gas detecting element 1 contains not less than 30 percent by weight of an oxidation catalyst, and is aged in advance in an environment that contains silicon vapor serving as a poisoning substance.

Abstract: A hydrogen sensor 25 has a fitting base plate 29 in which a gas-sensing chamber 34 is formed, a specimen gas intake 35 formed on said fitting base plate 29, opening toward an exit passage 24 and introducing hydrogen gas into the gas-sensing chamber 34, a gas-sensing element 39 held in the gas-sensing chamber 34 and adapted to sense hydrogen gas, and a water-repelling filter 44 covering the specimen gas intake 35.

Abstract: To provide a photoelectron measuring device that enables handling of samples in the atmosphere. A photoelectron measuring device that emits ultraviolet light from an ultraviolet light generating source 1 onto a sample S while changing the wavelength and detects the wavelength at which photoelectrons start to be discharged from the sample S, with the section up to an emission outlet 2 being housed in a non-oxygen environment and a sample stand 4 being disposed so that the distance from the emission outlet 2 to the sample S is 7 mm or less.

Abstract: The present invention provides an electrochemical gas sensor that can restrict to the extent possible interference errors.

Abstract: The invention provides a portable gas detector which is equipped with filters for removal of interfering gases, high in convenience for use, easy to exchange the filters, and easy to confirm the time the filters are exchanged. The portable gas detector has a housing in the form of a slim and flat box holdable by grasping with a hand, and a foreside half portion in the interior of the housing is provided as functional part region, in which a plurality of gas sensors are arranged in a state fixed by a holder and a cap, in the interior of which a gas flowing path has been formed. At a position corresponding to at least one gas sensor in the sensor cap exposed to the back surface of the housing, a filter assembly for removal of an interfering gas component related to the gas sensor is detachably provided.

Abstract: Disclosed is a small-sized joint for joining hydrogen gas running route-forming members, which can surely prevent the leakage of hydrogen gas, and a portable hydrogen flame ionization gas detector that can prevent the leakage of hydrogen gas to achieve high safety. The joint comprises a metallic base having an internal space at least one end of which is opened, and a ring-like sealing member composed of an elastic material and arranged at opening edge of the metallic base, wherein a hydrogen gas running route-forming member is fixed in a state inserted into an internal space of the metallic base through the sealing member, and the sealing member is squeezed to gastightly seal the space, whereby one hydrogen gas running route-forming member is removably joined. In the gas detector, the joint is used to form a hydrogen gas running route.

Abstract: A detecting material to detect formaldehyde at low concentration in the atmosphere in a short time is prepared by impregnating a base material containing at least silica gel with a coloring liquid containing 4-amino-4-phenyl-3-ene-2-one and a buffer solution and volatilizing the solvent.

Abstract: The invention provides a portable gas detector of a novel structure that is easy to be fabricated as a small-sized one handy to carry and high in convenience for use. The portable gas detector has a housing in the form of a slim and flat box holdable by grasping with a hand, and a foreside half portion in the interior of he housing is provided as a functional part region, and a rear half portion in the interior of the housing is provided as a battery part region. In the functional part region, one of 5 gas sensors is arranged at a curved portion in a gas sensor-arranging region of an L shape as a whole, and 2 gas sensors are arranged in a row in both lateral and vertical directions of the above gas sensor, respectively. A gas sucking means is arranged in a region, the 2 directions of which is sectioned by the gas sensor-arranging region.

Abstract: The invention provides an explosion-proof portable gas detector that is easy to be fabricated as a small-sized one handy to carry and high in convenience for use, and has explosion-proofness sufficient in a countermeasure against static electricity and high in reliability. The explosion-proof portable gas detector has at least gas sensors, a signal processing circuit, a display mechanism and a power source part within a housing in the form of a slim and flat box holdable by grasping with a hand. The whole or a part of the housing is formed of a static charge-controlling resin material having an insulating resistance value of at most 1 G? and a comparative tracking index of at least 90 V.

Abstract: A contact combustion-type gas sensor that can maintain its initial sensitivity over a long period of time in the presence of silicon vapor, wherein an induction portion 5 of a gas detecting element 1 contains not less than 30 percent by weight of an oxidation catalyst, and is aged in advance in an environment that contains silicon vapor serving as a poisoning substance.

Abstract: The invention provides an explosion-proof portable gas detector that is easy to be fabricated as a small-sized one handy to carry and high in convenience for use, and has explosion-proofness sufficient in a countermeasure against static electricity and high in reliability. The explosion-proof portable gas detector has at least gas sensors, a signal processing circuit, a display mechanism and a power source part within a housing in the form of a slim and flat box holdable by grasping with a hand. The whole or a part of the housing is formed of a static charge-controlling resin material having an insulating resistance value of at most 1 G? and a comparative tracking index of at least 90 V.

Abstract: The invention provides a portable gas detector of a novel structure that is easy to be fabricated as a small-sized one handy to carry and high in convenience for use. The portable gas detector has a housing in the form of a slim and flat box holdable by grasping with a hand, and a foreside half portion in the interior of he housing is provided as a functional part region, and a rear half portion in the interior of the housing is provided as a battery part region. In the functional part region, one of 5 gas sensors is arranged at a curved portion in a gas sensor-arranging region of an L shape as a whole, and 2 gas sensors are arranged in a row in both lateral and vertical directions of the above gas sensor, respectively. A gas sucking means is arranged in a region, the 2 directions of which is sectioned by the gas sensor-arranging region.