Patent ID: 8535510

Claim:
A substrate concentration measuring method for measuring a concentration of a substrate included in a specimen based on an output for measurement from an enzyme electrode when the enzyme electrode and the substrate are reacted with each other, the method comprising the following cycle: (i) a first washing of the enzyme electrode; (ii) a reaction of the enzyme electrode with the substrate in the specimen; (iii) a second washing of the enzyme electrode; and (iv) a reaction of the enzyme electrode with a reference solution whose substrate concentration is known, and the method further comprising: measuring a base output Rb measured when the first washing or the second washing of the enzyme electrode is completed; measuring an output for measurement Rs of the reaction of the enzyme electrode with the substrate in the specimen; measuring an output for correction Rm of the reaction of the enzyme electrode with the reference solution whose substrate concentration is known; calculating a difference ΔRm by subtracting Rb from Rm; calculating a difference ΔRs by subtracting Rb from Rs; and calculating the substrate concentration by correcting ΔRs by ΔRm.