ANALYZER, ABSORPTION PROPERTY COMPUTATION CIRCUIT, AND ANALYSIS METHOD

摘要

To provide an analyzer with which it is possible to the absorption properties of a substance to be measured with high accuracy in a measurement method that involves modulating an inrush current to a QCL.SOLUTION: The analyzer comprises: a QCL 14 for converting a drive signal that includes a cyclic waveform into measurement light of a mid-infrared region; a light detection unit 30 for outputting a detection signal that corresponds to the optical intensity of the measurement light having passed through a substance G to be measured; and a computation unit 40 for outputting information that represents the absorption properties of the substance to be measured, on the basis of the detection signal. The computation unit includes: a delay unit for applying, to one of the corrected waveform generated by a drive signal and the waveform of the detection signal, a time delay for the waveform of the other; an addition unit for adding one waveform having been time-delayed and the other waveform together; and a subtraction unit for generating a difference waveform between a waveform derived by time-inverting the waveform after the addition and the waveform after the addition, the computation unit repeatedly computing the difference waveform while changing the delay time and outputting a waveform after the addition when the absolute value of the difference waveform is smallest or information obtained from the waveform.SELECTED DRAWING: Figure 1