| CPC G01N 27/028 (2013.01) [G06T 2207/30136 (2013.01)] | 20 Claims |

|
1. A method for detecting and sizing a pit in a test object, the method comprising acts of:
(i) storing a signature library including signatures for multiple pit depths and multiple pit diameters in a non-transient computer-readable storage medium;
(ii) placing a sensor having a drive conductor and a plurality of sense elements proximate to the test object;
(iii) scanning the sensor across the test object;
(iv) during the scanning operating an immittance instrument to excite the drive conductor at a high frequency and a low frequency, and obtain sensor data by measuring the plurality of sense elements; and
(v) operating a processor to
(1) detect a pit by determining a calculated value exceeds a threshold,
the calculated value being a correlation between a first signature from the signature library and a high frequency response from the sensor data;
(2) estimate a pit diameter using the high frequency response; and
(3) estimate a pit depth from a low frequency response from the sensor data and a second signature from the signature library associated with the estimated pit diameter.
|