摘要:
A correction curve (FIG. 19) is prepared by plotting .sup.12 CO.sub.2 concentrations and .sup.13 CO.sub.2 /.sup.12 CO.sub.2 concentration ratios which are determined on the basis of a calibration curve and .sup.13 CO.sub.2 and .sup.12 CO.sub.2 absorbances of gaseous samples having the same .sup.13 CO.sub.2 /.sup.12 CO.sub.2 concentration ratio but known different .sup.12 CO.sub.2 concentrations. A gaseous test sample containing .sup.13 CO.sub.2 and .sup.12 CO.sub.2 as component gases is introduced into a cell, and spectrometrically measured. A .sup.12 CO.sub.2 concentration of the gaseous test sample is determined by way of the spectrometric measurement. A concentration ratio correction value is obtained on the basis of the correction curve and the .sup.12 CO.sub.2 concentration of the gaseous test sample thus determined. A measured .sup.13 CO.sub.2 /.sup.12 CO.sub.2 concentration ratio is divided by the concentration ratio correction value thus obtained for correction of the .sup.13 CO.sub.2 /.sup.12 CO.sub.2 concentration ratio. Thus, the measurement accuracy of the concentration ratios of the component gases can be improved. A breath sampling bag and gas measuring system is also disclosed where each is configured such that breath inlets of the gas measuring apparatus are prevented from being respectively connected to the wrong breath introduction pipes of the breath sampling bag.
摘要:
A correction curve (FIG. 19) is prepared by plotting 12CO2 concentrations and 13CO2/12CO2 concentration ratios which are determined on the basis of a calibration curve and 13CO2 and 12CO2 absorbances of gaseous samples having the same 13CO2/12CO2 concentration ratio but known different 12CO2 concentrations. A gaseous test sample containing 13CO2 and 12CO2 as component gases is introduced into a cell, and spectrometrically measured. A 12CO2 concentration of the gaseous test sample is determined by way of the spectrometric measurement. A concentration ratio correction value is obtained on the basis of the correction curve and the 12CO2 concentration of the gaseous test sample thus determined. A measured 13CO2/12CO2 concentration ratio is divided by the concentration ratio correction value thus obtained for correction of the 13CO2/12CO2 concentration ratio. Thus, the measurement accuracy of the concentration ratios of the component gases can be improved.
摘要:
As previous processing of measurement in which gas to be measured containing, as gas components, carbon dioxide 13CO2 and carbon dioxide 12CO2, is introduced into a cell, and in which the intensities of transmitted lights having wavelengths suitable for measurement of the respective gas components, are measured and then data-processed to measure the concentrations of the gas components, the air having a predetermined volume Va is sucked by a gas injection device 21, a gas exhaust valve V6 of a cell 11 is closed and the air stored in the gas injection device 21 is transferred to the cell 11 filled with the air at an atmospheric pressure, thereby to pressurize the cell inside. The pressure thus pressurized is measured as P. The cell volume Vc is subtracted from the product obtained by multiplying the sum. V0 of the volume Va and Vc the cell volume Vc, by the ratio P0/P in which P0 is the target pressure of the gas to be measured at which a calibration curve has been prepared for an isotope gas analysis and measurement, thus determining the one-time gas injection amount of the gas injection device 21. Thus, measured concentration variations based on changes in atmospheric pressure can be corrected.
摘要:
In an isotopic gas analyzer, a gas injector (21) is provided for pressurizing a gas specimen in cells (11a,11b). The pressurization of the gas specimen virtually produces the same effect as increasing the concentration of carbon dioxide in the gas specimen, thereby improving an S/N ratio for the analysis and hence data reproducibility.
摘要:
As previous processing of measurement in which gas to be measured containing, as gas components, carbon dioxide 13CO2 and carbon dioxide 12CO2, is introduced into a cell, and in which the intensities of transmitted lights having wavelengths suitable for measurement of the respective gas components, are measured and then data-processed to measure the concentrations of the gas components, the air having a predetermined volume Va is sucked by a gas injection device 21, a gas exhaust valve V6 of a cell 11 is closed and the air stored in the gas injection device 21 is transferred to the cell 11 filled with the air at an atmospheric pressure, thereby to pressurize the cell inside. The pressure thus pressurized is measured as P. The cell volume Vc is subtracted from the product obtained by multiplying the sum. V0 of the volume Va and Vc the cell volume Vc, by the ratio P0/P in which P0 is the target pressure of the gas to be measured at which a calibration curve has been prepared for an isotope gas analysis and measurement, thus determining the one-time gas injection amount of the gas injection device 21. Thus, measured concentration variations based on changes in atmospheric pressure can be corrected.
摘要:
A test gas sample containing carbon dioxide 13CO2 as a component gas is introduced into a cell, then the absorbance of light transmitted therethrough at a wavelength suitable for the component gas 13CO2 is determined, and the concentration of the component gas is determined on the basis of a calibration curve prepared through measurement on test gas samples each containing the component gas in a known concentration. Further, the concentration of water vapor contained in the test gas sample is measured, and the concentration of the component gas in the test gas sample is corrected in accordance with the measured water vapor concentration on the basis of a correction curve prepared through measurement on the test gas samples each containing water vapor in a known concentration (FIG. 4). With the spectrometry, the concentration ratio of the component gas can precisely be determined and corrected by measuring the moisture content in the test gas sample.
摘要:
A test gas sample containing carbon dioxide 13CO2 as a component gas is introduced into a cell, then the absorbance of light transmitted therethrough at a wavelength suitable for the component gas 13CO2 is determined, and the concentration of the component gas is determined on the basis of a calibration curve prepared through measurement on test gas samples each containing the component gas in a known concentration. Further, the concentration of water vapor contained in the test gas sample is measured, and the concentration of the component gas in the test gas sample is corrected in accordance with the measured water vapor concentration on the basis of a correction curve prepared through measurement on the test gas samples each containing water vapor in a known concentration (FIG. 4). With the spectrometry, the concentration ratio of the component gas can precisely be determined and corrected by measuring the moisture content in the test gas sample.
摘要:
A rotary stand (11) having a half-mirror (8) and a photodetector (10) mounted thereon, is continuously rotated around a first rotary shaft (A) passing through a sample (S), and set to a predetermined scattering angle. Simultaneously, a rotary reflecting mirror (7) is rotated at a predetermined angle to direct a reference li8ght (LR) to the half-mirror (8) at all times. The half-mirror (8) is also rotated at its own axis at a predetermined angle so that the direction of a scattering light (LS) at the light emitting side of the half-mirror (8) is identical with the direction of the reference lilght (LR). Accordingly, the reference light may be composed with the scattered light at an arbitrary scattering angle, enabling observation of the Doppler shift in the scattered light direction (FIG. 1).
摘要:
An exhalation collected in a breath bag capable of expanding and contracting is sucked into a gas inlet vessel 21 with a given volume (Va), and then the gas inlet vessel 21 is communicated by means of valve V2 with a cell 11 that is maintained at an atmospheric pressure by being pre-filled with a sample gas or reference gas. After the communication, the gas pressure is measured by a pressure sensor 16 attached to the cell 11. Whether the exhalation collected in the breath bag is below a given amount or not can be accurately judged.
摘要:
An exhalation collected in a breath bag capable of expanding and contracting is sucked into a gas inlet vessel 21 with a given volume (Va), and then the gas inlet vessel 21 is communicated by means of valve V2 with a cell 11 that is maintained at an atmospheric pressure by being pre-filled with a sample gas or reference gas. After the communication, the gas pressure is measured by a pressure sensor 16 attached to the cell 11. Whether the exhalation collected in the breath bag is below a given amount or not can be accurately judged.