| 摘要 |
PROBLEM TO BE SOLVED: To solve problems that a correct sensor output is hard to obtain by measurement using a conventional non-dilution method, and it takes much time to obtain a result and a large amount of cleaning liquid is used, because phenomena such as variations with time in electrode sensitivity is existed, and if sensor sensitivity relative to a specific object substance is calibrated for each time of measurement, virtually two times of measurements are needed, such as measurement of a sample solution and measurement of a calibration liquid. SOLUTION: The calibration liquid and a mixed sample are prepared. The mixed sample is made by mixing the calibration liquid and a measured sample at a prescribed ratio. By measuring each of them by a sensor, the solution contacting the sensor in measurement and that in calibration are made substantially equal. This holds down an error due to variations in pH, Cl-ion concentration, temperature, etc., of the sample to enhance measurement accuracy. When calibration is performed for each time of measurement, cleaning between the calibration and the measurement is omitted to make it possible to shorten measurement time and reduce the amount of cleaning liquid. |
