MEASURING DEVICE FOR CONCENTRATION OF OZONE

PURPOSE:To measure the concn. of ozone over a wide range at the rapid speed of response by calculating the concn. of ozone from the degree of rise of resistance value when the degree of rise exceeds the preset value in a thin film type ozone sensor of an n-type semiconductor. CONSTITUTION:The resistance of an n-type semiconductor ozone sensor 1 changes by the concn. of ozone. The change in the resistance value is measured in a measuring circuit 3 and A/D-converted 4 and inputted to a CPU 6 constituted of a microcomputer. The CPU 6 detects that ozone is attracted to a sensor 1 and the resistance value starts to be raised. The concn. of ozone is calculated by the degree of increase in the resistance at every constant short time while keeping both the resistance value and the time as a reference. Further when the resistance value reaches equilibrium, the concn. of ozone is calculated on the basis of this resistance value. Thereby the measured value of the concn. of ozone in a wide range is obtained at the rapid speed of response.