| 摘要 |
PURPOSE:To attain enhancment of the measuring accuracy of ion concn., by performing the temp. compensation of sensitivity and that of a zero point to ionic activity. CONSTITUTION:A semiconductor apparatus, which has an ion sensitive (IS)FET 11 for detecting the ionic activity of a solution M to be measured and a temp. element 13 for detecting the temp. of said solution M to be measured, is provided. Further, a constant current circuit 50 for flowing the drain current within a definite range to ISFET11 so that the source potential VS being the ionic activity of ISFET11 has linearity in relation to temp. and a digital operator 80 calculating the ion concn. of the solution M to be measured upon the reception of the signal VS for ISFET11 and the temp. signal D from the element 13 are provided. This operator 80 is quipped with a temp. sensitivity compensation means for correcting sensitivity to the activity of an ion by the signal VS from ISFET 11 and the signal D from the element 13 to digitally process the signals VS, D without adding any auxiliary signal to the signals VS, D. |
