PROBLEM TO BE SOLVED: To provide a concentration measurement apparatus for improving measurement accuracy.SOLUTION: The concentration measurement apparatus comprises a plurality of light emitting diodes, a transmissivity calculation means irradiated with light from the light emitting diodes to calculate the transmissivity of the light transmitted through a human body, and a concentration calculation means for calculating concentrations of a plurality of materials per unit optical path by using transmissivity calculated by the transmissivity calculation means. The reference light emitting diode has a center wavelength as a wavelength at which a fluctuation width of the transmissivity is large in comparison with the other light emitting diode. A linear distance between the wavelengths having a half value of the strength at the center wavelength is set so as to be narrow in comparison with the other light emitting diode.COPYRIGHT: (C)2011,JPO&INPIT【課題】測定精度を向上し得る濃度測定装置を提案する。【解決手段】複数の発光ダイオードと、当該発光ダイオードから照射され、人体を透過する光の透過率を算出する透過率算出手段と、透過率算出手段により算出される透過率を用いて、複数の物質の単位光路長あたりの濃度を算出する濃度算出手段とを有する。基準とすべき発光ダイオードは、透過率の変動幅が他の発光ダイオードに比べて大きく現れる波長を中心波長とし、該中心波長における強度の半値となる波長間の直線距離は、他の発光ダイオードに比べて狭く設定される。【選択図】図10
