Abstract: To appropriately take explosion-proof measures for an analysis device while suppressing consumption of a purge gas, an analysis device includes a filling unit, an irradiation unit, a propagation unit, a housing, a purge gas introduction unit, and an explosion-proof gas introduction unit. The filling unit is filled with a sample gas containing a gas to be measured. The irradiation unit emits measurement light to be used for analyzing the gas to be measured. The propagation unit is disposed between the filling unit and the irradiation unit, so as to form a propagation space for propagating the measurement light emitted from the irradiation unit to the filling unit. The housing houses the filling unit, the irradiation unit, and the propagation unit. The purge gas introduction unit introduces the purge gas into the propagation space. The explosion-proof gas introduction unit introduces an explosion-proof gas into the internal space of the housing.

Abstract: To suppress individual differences in intensity of output laser light for each semiconductor laser device as much as possible while suppressing generation of stray light in a package of the semiconductor laser device, provided is a semiconductor laser device used for optical analysis, including: a package that accommodates a semiconductor laser element therein; and a light reflection reducing member that is provided inside the package and suppresses reflection of light emitted from the semiconductor laser element, in which the light reflection reducing member is bonded to an inner surface of the package.

Abstract: A gas analysis device includes a probe tube, a flange, an optical system member, and heaters. The probe tube includes an optical path through which measurement light is projected onto a prescribed measurement region of a sample gas flowing through a flue and/or is received from the measurement region. The flange is fixed to the outer periphery of the probe tube and is attached to a pipe side wall. The optical system member projects measurement light onto the sample gas S within the measurement region and/or receives measurement light from the measurement region. The heaters are disposed within the flange and heats the portion where the probe tube and flange are fixed to each other.

Abstract: To check an influence to an absorbance due to a temporal variation of measuring light in an analyzing apparatus, the analyzing apparatus includes a reference gas filling space, a spectrum generating portion, and a spectrum comparing portion. The reference gas filling space is formed on an optical path of measuring light and is filled with a reference gas different from a measurement target gas at a first concentration. The spectrum generating portion generates measured spectrum data, associating a wavelength of a detection light beam as the measuring light after passing through the reference gas filling space with a relative intensity of the detection light beam. The spectrum comparing portion calculates a difference between the measured spectrum data and reference absorption spectrum data obtained by measuring in advance an absorption spectrum of the reference gas at the first concentration by a direct absorption method.

Abstract: A gas analyzing apparatus includes a plurality of light sources, an inlet, a light detector, and an analyzing unit. The plurality of light sources simultaneously output a plurality of measurement light beams. The inlet introduces the plurality of measurement light beams into a measurement space. The light detector measures total intensity. The analyzing unit analyzes the target gases based on a difference between a measured target intensity and a reference intensity, in which the measured target intensity is a total intensity measured by the light detector after passing through the measurement space in which one of the target gases exists, while the reference intensity is the total intensity measured by the light detector after passing through the measurement space in which none of the target gases exists.

Abstract: A gas analysis device includes a probe tube, a flange, an optical system member, and heaters. The probe tube includes an optical path through which measurement light is projected onto a prescribed measurement region of a sample gas flowing through a flue and/or is received from the measurement region. The flange is fixed to the outer periphery of the probe tube and is attached to a pipe side wall. The optical system member projects measurement light onto the sample gas S within the measurement region and/or receives measurement light from the measurement region. The heaters are disposed within the flange and heats the portion where the probe tube and flange are fixed to each other.

Abstract: A thermometer comprises an emitting unit, a light receiving unit, a light collecting unit, and a calculation unit. The emitting unit is configured to emit a measurement light into a flue, wherethrough a gas that contains light scattering particles flows. The light receiving unit is configured to receive, of the measurement light, scattered measurement light scattered by the light scattering particles. The light collecting unit is configured to collect the scattered measurement light existing on the light receiving axis. The calculation unit is configured to calculate the temperature inside the flue based on an intensity ratio of absorption spectra at a plurality of wavelengths.

Abstract: A method of calibrating a gas analysis apparatus that measures the moisture concentration in a gas using a radiating unit includes a moisture concentration measurement value calibrated based on the relationship between the intensity of an absorption spectrum of moisture of a concentration to be measured and the intensity of an absorption spectrum of an other component gas that can be measured by the radiating unit, for which the relationship to the intensity of the absorption spectrum of moisture of the measured prescribed concentration is known, and based on the intensity of an absorption spectrum obtained by measuring the other component gas.

Abstract: Provided is an optical analyzer which can promote enhancement of measurement sensitivity, cost reduction, size reduction, structural flexibility, disturbance resistance, and the like, at the same time. A laser device to be used in such optical analyzer is also provided. An optical analyzer comprises a laser light source (2); a wavelength selection element (3) for selecting and leading out light having a wavelength substantially equal to the absorption wavelength of an analysis object from among light outputted from the laser light source (2); an optical detection means (5) for detecting the intensity of light red out from the wavelength selection element (3); and a drive current control means (6) for increasing or decreasing the drive current of the laser light source (2) near a specified current value thereof for outputting light of the absorption wavelength, and setting the drive current at such a current value as the intensity of light detected by the optical detection means (5) has a peak value.

Abstract: A method for producing a nitrobenzene compound represented by general formula (2), wherein R1 and R5 are the same or different, and each is a halogen atom or another functional group, and R2, R3, and R4 are the same or different, and each is a hydrogen atom or another functional group, comprises oxidizing an aniline compound represented by general formula (1), wherein R1, R2, R3, R4, and R5 are the same as described above, with hydrogen peroxide in the presence of a tungsten compound under an acidic condition, followed by oxidation with hydrogen peroxide under a neutral to alkaline condition.

Abstract: A gas analysis apparatus includes: a first reflector that reflects measurement light from a light emitting unit disposed outside a gas flue wall and transmitted through a sample gas. A light receiving unit outside the gas flue wall receives measurement light reflected by the first reflector. A second reflector outside the gas flue wall reflects measurement light toward the light receiving unit. A computing unit analyzes sample gas by allowing the measurement light to be reflected by the first reflector and performs correction or calibration of the gas analysis apparatus using known substances within an associated containing unit along the light path between the light emitting unit and the second reflector by allowing measurement light to be reflected by the second reflector. A switching unit outside the gas flue wall selectively removes or inserts the second reflector from the light path during component concentration analysis and correction or calibration, respectively.

Abstract: A gas measurement apparatus measures a target gas. The gas measurement apparatus includes a light source, a first light receiving apparatus, a first phase-sensitive detection apparatus, an R calculation unit, and a setting unit. The light source oscillates a laser light that has a central wavelength determined by a main current and is modulated according to a modulation current, with the central wavelength being varied. The first light receiving apparatus outputs a detection signal according to an intensity of the laser light transmitted through a standard sample. The first phase-sensitive detection apparatus obtains a second harmonic component oscillated at a harmonic frequency ?2 twice as large as a modulation frequency ?1. The R calculation unit calculates a peak-bottom ratio R. The setting unit sets a width of wavelength modulation of the laser light so that the peak-bottom ratio R satisfies a predetermined condition.

Abstract: A thermometer comprises an emitting unit, a light receiving unit, a lens unit, and a calculation unit. The emitting unit is configured to emit a measurement light into a flue, wherethrough a gas that contains light dispersing particles flows. The light receiving unit is configured to receive, of the measurement light, dispersed measurement light dispersed by the light dispersing particles. The lens unit is configured to set its focal point at a prescribed position inside the flue and along the light receiving axis. The calculation unit is configured to calculate the temperature inside the flue based on an intensity ratio of absorption spectra at a plurality of wavelengths.

Abstract: A gas analysis apparatus includes: a first reflector that reflects measurement light from a light emitting unit disposed outside a gas flue wall and transmitted through a sample gas. A light receiving unit outside the gas flue wall receives measurement light reflected by the first reflector. A second reflector outside the gas flue wall reflects measurement light toward the light receiving unit. A computing unit analyzes sample gas by allowing the measurement light to be reflected by the first reflector and performs correction or calibration of the gas analysis apparatus using known substances within an associated containing unit along the light path between the light emitting unit and the second reflector by allowing measurement light to be reflected by the second reflector. A switching unit outside the gas flue wall selectively removes or inserts the second reflector from the light path during component concentration analysis and correction or calibration, respectively.

Abstract: A measurement unit used in an analyzing apparatus for measuring concentrations of component gases in a sample gas comprises a light emitting unit configured to emit a measurement light to the sample gas, a light receiving unit configured to receive the measurement light on a light receiving plane, a purge air introducing unit configured to introduce a purge air into a vicinity of at least one of the light emitting unit and the light receiving unit, and a condensing lens arranged in an optical path of the measurement light from the light emitting unit to the light receiving unit, the condensing lens being configured to condense the measurement light within the light receiving plane of the light receiving unit, a propagation path of the measurement light being varied by a thermal lens effect caused by a temperature difference between the sample gas and the purge air.

Abstract: A method for producing a nitrobenzene compound represented by general formula (2), wherein R1 and R5 are the same or different, and each is a halogen atom or another functional group, and R2, R3, and R4 are the same or different, and each is a hydrogen atom or another functional group, comprises oxidizing an aniline compound represented by general formula (1), wherein R1, R2, R3, R4, and R5 are the same as described above, with hydrogen peroxide in the presence of a tungsten compound under an acidic condition, followed by oxidation with hydrogen peroxide under a neutral to alkaline condition.

Abstract: A probe for gas analysis is provided in a pipe through which sample gas flows. The probe includes a tubular member and one or more sample gas inflow portions. The tubular member is disposed to cross a flow of the sample gas, and includes a measurement field to which the sample gas is introduced. The one or more sample gas inflow portions are provided in the tubular member. The sample gas flows around, and flows into the measurement field through the one or more sample gas inflow portions.

Abstract: An air-driven shutter device is used in an optical analyzer. The optical analyzer includes a measurement field to which a sample is supplied, a light-emitting unit measurement field for emitting measuring light to the sample, a light-receptive unit for receiving the measuring light that has passed through the sample, and a purge air supplying unit for supplying purge air. The air-driven shutter device includes a shutter and a shutter opening and closing mechanism. The shutter is disposed between the light-emitting unit and/or the light-receptive unit and the measurement field. The shutter opening and closing mechanism keeps the shutter open with pressure of the gas supplied from the purge air supplying unit, and closes the shutter when the pressure of the gas supplied from the purge air supplying unit becomes lower than a predetermined level.

Abstract: The measurement sensitivity is improved by suppressing the surrounding temperature influence as much as possible, while realizing scale reduction, and by enlarging the detection signal, while reducing the production errors in enclosing a reference gas. Provided is a thermal conductivity sensor that detects thermal conductivity of a sample gas by using a Wheatstone Bridge circuit constructed in such a manner that measurement resistors that are brought into contact with the sample gas are disposed on a first side, and reference resistors that are brought into contact with a reference gas are disposed on a second side, and comparing the potential difference between connection points of the reference resistors and the measurement resistors. The measurement resistors disposed on the first side are assembled in one measurement space, and the reference resistors disposed on the second side are assembled in one reference space.

Abstract: A probe for gas analysis is provided in a pipe through which sample gas flows. The probe includes a tubular member and one or more sample gas inflow portions. The tubular member is disposed to cross a flow of the sample gas, and includes a measurement field to which the sample gas is introduced. The one or more sample gas inflow portions are provided in the tubular member. The sample gas flows around, and flows into the measurement field through the one or more sample gas inflow portions.