ELECTROSTATIC CAPACITY MEASURING METHOD

PROBLEM TO BE SOLVED: To simultaneously carry out delay characterizing and computation of electrostatic capacity by discharging electrostatic capacity once charged, and searching for electrostatic capacity front the total quantity of current flowing out at the time. SOLUTION: A switch 7 is changed to be in the non-conductive state, and a potential control means 6 is set so that the potential of the output terminal 2 of a cell 1 as the electrostatic capacity of a measuring object becomes logic '1'. When the potential change of the output terminal 2 disappears, the potential control means 6 is set so that the state of the output terminal 2 becomes high impedance. Hereat, the switch 7 is changed to be in the conductive state, and current in an ammeter 8 is integrated by an integration means 10, until the current flowing in the ammeter 8 becomes zero. When the current flowing in the ammeter 8 becomes zero, the integrated result of the integration means 10 is delivered to a capacity computing means 11, and C=Q/V is computed so as to obtain the electrostatic capacity C. Hereby, delay characterizing and computation of the electrostatic capacity can be simultaneously carried out.