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 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 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:
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. The laser light source (2), the wavelength selection element (3), and the optical detection means (5) are mounted on a single substrate (11) which can regulate the temperature to a constant level.
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. The laser light source (2), the wavelength selection element (3), and the optical detection means (5) are mounted on a single substrate (11) which can regulate the temperature to a constant level.
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 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.