Apparatus and method for sensor detection

摘要

Apparatus for detecting presence of a sensor includes a signal source for providing an excitation signal for the sensor. A detector circuit detects a response signal from the sensor in response to the excitation signal for presence detection. A switch is responsive to a control signal for switching between a first switch state for coupling the signal source to the sensor and a second switch state for coupling the detector circuit to the sensor. A controller provides the control signal and analyzes the detected response signal. The excitation signal can be a chirp signal that spans a range of frequencies. First and second tests of the sensor are conducted with the presence of the sensor determined from the first and second tests. Parameters of the detection including gain can be changed for the first and second tests to provide a more accurate test result.