Patent ID: 7239904

Claim:
A component concentration measurement method, comprising: a first step of irradiating light onto an object of measurement with the object of measurement in a first magnetic field state, and detecting a state of light from the object of measurement at this time; a second step of irradiating light onto the object of measurement with the object of measurement in a second magnetic field state different from the first magnetic field state, and detecting a state of light from the object of measurement at this time; and a third step of calculating the concentration of a target component based on a detection result in the first step and a detection result in the second step; wherein in the first and second steps, the state of light from the object of measurement is detected as the absorbance or the amount of light; and wherein in the third step, the concentration of the target component is calculated based on the difference Δ between the absorbance or the amount of light measured in the first step and the absorbance or the amount of light measured in the second step.