| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus to highly accurately measure a constituent concentration of an object to be measured with a small number of measurement items while achieving reduction in a measurement time.SOLUTION: Laser diodes 1-1 and 1-2 modulate intensity of light of two waves with different wavelengths by the same frequency and by signals of different phases, and irradiate an object 11 to be measured with the light. An acoustic sensor 6 detects a photoacoustic signal generated from an object 11 to be measured by a photoacoustic effect, and coverts it to an electric signal proportional to acoustic pressure. An information processing device 10 changes the power of light emitted from the laser diode 1-2, measures the power of light and the intensity of an electric signal output from a lock-in amplifier 9, approximates the relationship between the intensity of the electric signal and the power of light by a numerical expression, estimates the power of light at a true point where the intensity of the electric signal reaches a minimum level based on the result of the approximation, and derives a constituent concentration of an object to be measured contained in the object 11 to be measured based on the result of the estimation.SELECTED DRAWING: Figure 1 |
