Patent ID: 7936175

Claim:
A method for testing of a transducer, which transducer includes a sensing element having an impedance and an associated conditioning preamplifier, said method comprising the steps of: providing a test signal for introduction into an input terminal of the preamplifier when testing is desired, providing a mode control signal when testing is desired, wherein the test signal is concomitant the mode control signal so that the mode control signal is superposed on the input terminal as well, and so that together the test signal and mode control signal constitute test signalling, decoding of said mode control signal in a local circuit in said preamplifier which indicates that testing is desired, enabling, based on the decoding of the mode control signal, a routing of said test signal into said input terminal of said preamplifier, and analyzing, when the test signal is selectively routed to the input terminal, an output of the preamplifier indicative of the impedance of the sensor tested to determine electrical properties of said transducer from a remote location.