A system and method for obtaining an estimate of the concentration of an odor in an air sample from data obtained by evaluating the sample with a sensor-array type electronic nose. Principal components analysis is applied to a set of air sample data including sensor-array data obtained from evaluating the air sample with the sensor-array type electronic nose and measurements of the humidity of the air sample and clean reference air used by the electronic nose to obtain a predetermined number of principal components of the air sample data. The principal components obtained from the air sample are used as inputs to a neural network to obtain as output an estimate of the concentration of the odor in the air sample. The neural network uses parameters obtained by using an olfactometer to obtain discrete measurements of odor concentration from each of a plurality of calibration samples of air containing the odor, using the sensor-array type electronic nose to obtain a discrete set of calibration data from each of the calibration samples, each set including sensor-array data and measurements of the humidity of the calibration sample and the clean reference air used by the electronic nose, applying principal components analysis to each set of calibration data to obtain a discrete set of the predetermined number of principal components, and training a neural network using the sets of principal components as input data and the corresponding measured odor concentrations as expected output to obtain the parameters of a trained neural network.
It is desirable to provide a gas chromatography type of chemical analysis method for estimating the change of body smell with progressive ageing of a living subject over a period of years by 1) utilization of the smell distinguishing ability of an experimental animal, 2) instrumental analysis, or 3) a combination of them. The present inventors found that the amounts of several volatile organic substances (e.g., 2-phenylacetamide, indole and phenol) present in mouse urine as substances responsible for the body smell are increased or decreased with ageing. The change in body smell with ageing of an animal can be estimated by quantitatively analyzing these compounds by an instrumental analysis method such as Y-shaped labyrinth method (involving live animals in a maze), gas chromatograph (GC) or high performance liquid chromatography (HPLC).
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 S1 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 .theta. 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.
The intensity of an odour can be quantified by determining what is the response of an odour sensing device to that odour, then transforming the response data to an odour intensity value based on transformation data relating to a set of selected reference odours. The transformation data includes organoleptic data indicating how odour intensity values assigned to the set of reference odours by a sensory panel depend upon the concentration of the reference compounds and includes data indicating how the response data of the odour sensing device when exposed to the set of reference odours depends upon the concentration of the reference compounds. The reference odours may be basic odours defining the dimensions of a multi-dimensional space in which odours can be defined.
This invention relates to an integrated apparatus and method for inspection of a container adapted to hold a pressurized gas. The integrated apparatus comprises (i) an imaging device configured to obtain image data corresponding to the container and to transmit the image data to a central station, (ii) a sound detecting device configured to obtain acoustic data corresponding to the container and to transmit the acoustic data to the central station, (iii) optionally an odor detecting device configured to obtain odor data corresponding to the container contents and to transmit the odor data to the central station, (iv) wired or wireless electronic circuits in communication between each device and the central station for transmitting signals, the signals including the data, to the central station, and (v) the central station configured to receive the data transmitted by each device.
Disclosed herein is a method and apparatus for analyzing, sensing and measuring the concentrations of various gases, including NO.sub.x, hydrocarbons, carbon monoxide and oxygen, in a multi-component gas system using chemical sensors and chemical sensor arrays. The sensors and sensor arrays use chemo/electro-active materials to analyze and detect the presence of gases.
