Nippon Sanso Corporation

Shang-Qian Wu

Yoshio Ishihara

Tetsuya Kimijima

Tetsuya Sato

Hiroshi Masusaki

Koh Matsumoto

Jun-ichi Morishita

Tetsuya Satou

A method and an apparatus for measuring the concentrations of the components of a fluid are described, which can be used to measure the concentrations of the components continuously in real time and to monitor a high pressure gas, and is suitably used for in-line monitoring. In the method and the apparatus, a fluid sample is conducted through a measuring tube, wherein the measuring tube has a small aperture with a constant diameter in a fluid flow path. The pressure difference (P&#x2212;P) between the upstream and the downstream of the small aperture and the flow rate at the downstream of the small aperture are measured to determine the concentrations of the components of the fluid.

Method and apparatus for measuring concentrations of components of fluid

A method and an apparatus for measuring the concentrations of the components of a fluid are described, which can be used to measure the concentrations of the components continuously in real time and to monitor a high pressure gas, and is suitably used for in-line monitoring. In the method and the apparatus, a fluid sample is conducted through a measuring tube, wherein the measuring tube has a small aperture with a constant diameter in a fluid flow path. The pressure difference (P &minus;P ) between the upstream and the downstream of the small aperture and the flow rate at the downstream of the small aperture are measured to determine the concentrations of the components of the fluid.

Method and apparatus for measuring nitrogen in a gas

A gas spectroscopic analysis device for analyzing a trace impurity in a sample gas by obtaining the second derivative spectrum of the light absorption intensity by passing frequency modulated diode laser light through a low-pressure sample gas is provided with a modulation amplitude calculating device ( ) for controlling the modulation amplitude of the laser light in accordance with the characteristics of diode laser ( ); a spectrum calculating device ( ) for calculating the peak absorption intensity and the wavelength interval between the minimum values on the left and right hand of the peak in the second derivative spectrum obtained by measurement; and a pressure adjusting device ( ) for controlling the pressure inside measuring gas-cell ( ) so that the value of the absorption intensity obtained at spectrum calculating device ( ) becomes maximal. The optimal value of the modulation amplitude of the laser light is set so that the wavelength interval between the minimum values on the left and right hand of the peak in the second derivative spectrum is 0.0116 nm. The measurement pressure is optimized by setting the modulation amplitude to an optimal value.

Gas spectrochemical analyzer, and spectrochemical analyzing method

Analysis method for gases and apparatus therefor

A device and method for measuring an impurity in a trace concentration in a gas to be measured by infrared spectroscopic analysis employing a diode laser are provided. In order to carry out analysis with high sensitivity and high accuracy, the gas to be measured is directed into sample cell 5 and placed in a low pressure state by a pump 16. Infrared light from the wavelength region in which strong absorption peaks from the impurity can be obtained are oscillated from the diode laser 1, and a derivative absorption spectrum is measured by passing the infrared rays through sample cell 5 and reference cell 8 which is filled with the impurity alone. The spectrum for the gas to be measured and the spectrum for the impurity alone are compared, and the impurity is identified by confirming a plurality of absorption peaks originating from the impurity. Determination of the impurity is then carried out from absorption intensity of the strongest peak. In the case where molecules of the gaseous impurity form clusters in the gas to be measured, analysis is carried while dissociating the clusters by irradiating light having a photon energy of 0.5 eV or greater. The device and method are particularly suitable for carrying out analysis of trace quantities of impurities present in the gases which are used as materials for semiconductor manufacturing.

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Tokyo, Japan

Shang-Qian Wu