Patent ID: 7301353
Filing Date: 2007-11-27
Classification: G01D,G01R,H03F

Abstract:
1. A sensor element for providing a sensor signal, comprising: a measuring element having first, second, third and fourth contact terminals; a first output terminal and a second output terminal; switching equipment for connecting the first or fourth contact terminals to the first output terminal, and for connecting the second or third contact terminals to the second output terminal; a unit for applying a controlled variable between the first and second contact terminals or between the third and fourth contact terminals; a control unit so as to, in a first measuring cycle, in a first measuring phase, apply a first controlled variable having a first polarity between the first and second contact terminals, connect the third contact terminal to the second output terminal, and connect the fourth contact terminal to the first output terminal so as to provide a first measurement value, subsequently in a second measuring phase, apply a second controlled variable, having a polarity opposed to the first polarity, between the first and second contact terminals, connect the third contact terminal to the second output terminal, and connect the fourth contact terminal to the first output terminal so as to provide a second measurement value; subsequently in a third measuring phase, apply the first controlled variable having the first polarity between the third and fourth contact terminals, connect the first contact terminal to the first output terminal, and connect the second contact terminal to the second output terminal so as to provide a third measurement value; subsequently in a fourth measuring phase, apply the second controlled variable, having the polarity opposed to the first polarity, between the third and fourth contact terminals, connect the first contact terminal to the first output terminal, and connect the second contact terminal to the second output terminal so as to provide a fourth measurement value; subsequently a determinator for determining the sensor signal, configured to provide the sensor signal on the basis of a difference between the first measurement value and the second measurement value, and a difference between the third measurement value and the fourth measurement value.