Shimadzu Corporation

Jun-ichi Kita

Hisamitsu Akamaru

Hirokazu Taniguchi

Hiroyuki Kishihara

Kunihiko Ohkubo

Motoo Kinoshita

Kunihiko Okubo

Hiroshi Nakano

Mitsuyoshi Yoshii

Yoshihiro Aoyama

Keiso Kawamoto

Yoshiharu Iwasaki

The present invention provides an odor measuring apparatus capable of assuredly detecting and evaluating such odors that cannot be detected by a measurement apparatus using conventional odor sensors. In an embodiment of the present invention, a gas sample to be measured is introduced into the columnof a gas chromatographto temporally separate it into odor components, which are then introduced into a mass spectrometer (MS)and an odor discriminatorin parallel. The data processorcreates a chromatogram and/or a mass spectrum from the detection signals generated by the detectorof the MS, and also calculates the similarity of each odor component to standard odors and/or the degree of contribution from the detection signals generated by the detection circuitof the odor discriminator. The processordisplays a similarity radar chart or similar graphic information on the display, where each peak present on the chromatogram is associated with the information. Even if the odor to be measured is a mixed odor, the GCtemporally separates it into sample components, and each sample component can be assuredly and objectively detected by the odor discriminator

Odor measuring apparatus

The present invention provides an odor discriminating apparatus capable of determining the similarities or differences between plural odors with respect to the odor quality and the odor intensity, and showing the measurement result in such a manner that helps the user to correctly understand the result. According to the present invention, plural samples of a reference odor gas, each sample having a different concentration, are measured with m pieces of odor sensors. Based on the measurement result, a calibration curve is created in an m-dimensional space formed by the detection signals of the m pieces of odor sensors (Steps S&#x2013;S). Next, a measurement point Urepresenting the measurement result of a subject odor is plotted in the m-dimensional space. Based on the spatial relation between the measurement point Uand the calibration curve, an index &#x3b8; indicating the difference in the quality between the two odors and another index In indicating the difference in the intensity between the two odors are calculated (Steps S&#x2013;S). Then, using a predetermined conversion rule, &#x3b8; and In are converted into an odor quality difference index and an odor intensity difference index, and the measurement result is plotted on an odor similarity evaluation graph whose abscissa and ordinate correspond to the two indices, respectively (Step S).

Odor discriminating apparatus

The present invention proposes an odor measuring apparatus capable of determining the similarity of the odor of an unknown sample with high objectivity and performing measurements with sensitivity similar to that of the human nose. According to a mode of the invention, an m-dimensional space is created from detection signals of m pieces of odor sensors, and a standard odor vector S representing the result of measurement of a standard odor and another vector Sx representing the result of measurement of an unknown sample are drawn in the space. Then, from the angle &thgr; between the two vectors, a degree of similarity is determined within the range from 0 to 100%, where the degree of similarity is corrected taking account of the difference in sensitivity between the odor sensor and the human nose. The degree of similarity of the unknown odor is calculated for each of plural standard odors measured beforehand, and which standard odor is the closest to the odor of the unknown sample is objectively shown by numeral values.

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.

Devices for measuring gases with odors

In order to improve a signal-to-noise ratio of an optical detector with a light source and a photodetector of ordinary performance, light is applied from an ultraviolet lamp 6 which is provided on one side of a capillary cell 4 while light generated from the capillary cell 4 is received by an array photodetector 14 provided on the other side thereof. A lens 18 makes positions on the capillary cell 4 to correspond to those on the array photodetector 14. A data processing part 20 temporarily stores corrected and incorporated detection outputs, and calculates integrated averages while displacing time bases so that those of the same sample portions are overlapped with each other.

Optical detector for capillary chromatography

A thermal photodetector includes a thermal photodetector element and a support stand for supporting the thermal photodetector element. The support stand is made of a material of which heat conduction is relatively small, and is thermally connected to and mounted on a mount of which temperature is controlled to a predetermined temperature. The sizes of the support stand are determined such that the quantity of heat conduction in a heat conduction passage from the thermal photodetector element to the mount is equal to a predetermined quantity. The method of manufacturing this thermal detector includes the steps of exposing, to light, a photosensitive glass plate having a thickness corresponding to the height of a support stand of a thermal photodetector to be manufactured. The light exposure is made with the use of a mask having a shape which corresponds to the shape in transverse section of the support stand. The photosensitive glass plate is adhered to pyroelectric crystal plate provided on one surface thereof with an electrode. The surface of the pyroelectric crystal plate on which the electrode is mounted faces the photosensitive glass plate. The surface of the pyroelectric crystal plate opposite to the adhered surface is polished. The light-sensed portion of the photosensitive glass plate is then removed.

Growing community of inventors

Kyoto-fu, Japan

Jun-ichi Kita