Patent ID: 8412477

Claim:
A method for digital measuring a capacitive sensor CX using a charge balancing procedure comprising the steps: a. first converting, with a charge balance frequency converter, a value of the capacitance of the capacitive sensor into a number Z 1 of pulses with a first clock frequency f 1 ; b. second converting, with the charge balance frequency converter, the value of the capacitance of the capacitive sensor into a number Zm of pulses with a second clock frequency fm; c. comparing results of the first converting and the second converting; d. calculating a real capacitance and a value of a shunt resistance of the capacitive sensor with a function depending on the first and the second converting results if the results are not equal; and e. calculating the real capacitance of the capacitive sensor with a function depending on the result of the second converting if the results are equal.