Shimadzu Corporation

Hiroshi Nakano

Motoo Kinoshita

Junichi Kita

Kunihiko Okubo

Keiso Kawamoto

Kunihiko Ohkubo

Jun-ichi Kita

Hisamitsu Akamaru

Ryutaro Oda

Mitsuyoshi Yoshii

An isotope gas measuring apparatus for measuring concentrations of components in a sample gas includes two sample cells through which the sample gas passes; a control cell filled with a gas having no absorbance at a wavelength of infrared light to be measured; a light source irradiating infrared light to the sample cells and the control cell; an optical coupler for coupling light permeated from the sample cells and the control cell; a first interference filter disposed between one sample cell and the optical coupler; a second interference filter disposed between the other sample cell and the optical coupler; and an optical detector for detecting infrared light from the optical coupler. The apparatus can minimize an influence of drift, and have a simple structure.

Isotope gas measuring apparatus

In an odor measuring apparatus, a plurality of detection outputs with respect to a sample gas is obtained by a plurality of odor sensors having different response characteristics. In an odor fractionation processing section, based on the detection outputs, it is determined which one of a plurality of predetermined odor categories the odor of the sample gas belongs to. In case of calculating an odor index from the detection outputs, the same regression line can be utilized for the same odor category. An odor index calculating section utilizes regression coefficients determined in advance for each odor category, to thereby calculate the odor index. Accordingly, without using an organoleptic test by panels, the odor index can be obtained easily and accurately.

Odor measuring apparatus

An odor measuring device has a collector tube containing an adsorbent which adsorbs sample components with odor at normal temperatures and desorbs them when heated. Flow routes for a sample gas containing sample components to be detected and an inactive gas are connected through valves to this collector tube. Initially, a sample gas containing sample components with odor is introduced into the collector tube at normal temperature such that the sample components to be detected are adsorbed to the adsorbent. Thereafter, the valves are switched such that the inactive gas is introduced into the collector tube while its temperature is increased by a heater, causing the sample components to be desorbed into the inactive gas and to be transported into an odor sensor. If odor sensors requiring oxygen for detection are used, an oxygen-containing gas such as air is mixed into the inactive gas after the latter has passed through the collector tube such that deterioration of the adsorbent by oxidation can be prevented.

Devices and methods for measuring odor

A device for measurement of an odor component in a sample gas prepares many target gases to be actually measured by a plurality of sensors with different response characteristics, each containing the odor component at a different concentration. Detection signals from these sensors are analyzed by a method of multivariate analysis such as the principal component analysis, and the odor component is characterized on the basis of such an analysis. For preparing the target gases, the sample gas containing the odor component is passed through a collector tube containing an adsorbent which adsorbs this odor component at normal and subnormal temperature and desorbs it when heated. After a specified amount of the odor component is adsorbed to the adsorbent, the tube is heated and an inert gas serving as carrier gas is passed through such that the desorbed odor component is carried to the detectors as a target gas. The concentration of the odor component in such a target gas is controlled by the manner of flow of the carrier gas. In order to obtain a dependable result from such an analysis, response characteristics of each of the sensors may be analyzed by examining the relationship between the outputted detection signal and the concentration of the odor component in the target gas. Only those of the sensors which show a monotonically varying or linear response characteristics may be considered trustworthy and only the detection signals from such trustworthy detectors may be used for the analysis.

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Kyoto, Japan

Hiroshi Nakano