APPARATUS AND METHOD FOR CALIBRATION OF MOISTURE METER

PROBLEM TO BE SOLVED: To obtain an apparatus and a method in which the moisture of an aggregate to be measured is measured with high accuracy by using a working curve optimum for the aggregate to be measured and in which the measuring accuracy of the aggregate, which is updated so as to correspond to a change in the aggregate is maintained. SOLUTION: The moisture of an aggregate, obtained by a moisture meter sensor 1 is converted into a prescribed voltage value by an I/F box 2 so as to be inputted to a slump control device 3. On the basis of an initialized working curve, the slump control device 3 computes and outputs the moisture value of the aggregate according to a voltage value which is outputted by the moisture meter sensor 1. In an initialization operation, a voltage output at a time when the moisture meter sensor 1 does not measure the aggregate is set as the moisture value as 0% of the aggregate so as to be registered as a first point. As a second point, the moisture value of the aggregate which is measured by the moisture meter sensor 1 is registered. By using the two points, a working curve is generated so as to be stored as an initialization value. In an automatic updating operation, a correlation between a surface moisture rate which is output by a theoretical expression model and a measured moisture which is obtained from the moisture meter sensor 1 is monitored, and the part of the corresponding moisture rate on the working curve is shifted to a corresponding value.