An EC (Eddy Current) system for detecting flaws in a test object, the system comprising: (a) an EC array probe configured with a sensor arrangement including: (i) a plurality of first type EC sensors which are orthogonal sensors arranged in channels and configured to induce eddy currents in the test object and to sense and output first signals representative of flaws in the test object; characterized in that (ii) a plurality of second type EC sensors which are absolute sensors configured to produce from the test object second signals indicative of a lift-off distance of said orthogonal and absolute EC sensors (128, 129) relative to said test object, said EC coil arrangement being configured so that a pre-determined ratio is established between said second signals and said first signals, at different lift-off distances; (b) a setup table comprising calibration values for said orthogonal EC sensors with corresponding lift-off compensation values for said channels based on said second signals; and (c) an acquisition unit responsive to said calibration and lift-off compensation values in said setup table and to said second signals and configured to convert said first signals obtained from said orthogonal EC sensors during actual testing of said test object, so as to obtain third signals which are representative of said flaws in said test object, said third signals being substantially independent of actual lift-off distances prevailing between said EC sensors and said test object at the time of obtaining said first signals doing said actual testing. (a) an EC array probe configured with a sensor arrangement including: (i) a plurality of first type EC sensors which are orthogonal sensors arranged in channels and configured to induce eddy currents in the test object and to sense and output first signals representative of flaws in the test object; characterized in that (ii) a plurality of second type EC sensors which are absolute sensors configured to produce from the test object second signals indicative of a lift-off distance of said orthogonal and absolute EC sensors (128, 129) relative to said test object, said EC coil arrangement being configured so that a pre-determined ratio is established between said second signals and said first signals, at different lift-off distances; (i) a plurality of first type EC sensors which are orthogonal sensors arranged in channels and configured to induce eddy currents in the test object and to sense and output first signals representative of flaws in the test object; characterized in that (ii) a plurality of second type EC sensors which are absolute sensors configured to produce from the test object second signals indicative of a lift-off distance of said orthogonal and absolute EC sensors (128, 129) relative to said test object, said EC coil arrangement being configured so that a pre-determined ratio is established between said second signals and said first signals, at different lift-off distances; (b) a setup table comprising calibration values for said orthogonal EC sensors with corresponding lift-off compensation values for said channels based on said second signals; and (c) an acquisition unit responsive to said calibration and lift-off compensation values in said setup table and to said second signals and configured to convert said first signals obtained from said orthogonal EC sensors during actual testing of said test object, so as to obtain third signals which are representative of said flaws in said test object, said third signals being substantially independent of actual lift-off distances prevailing between said EC sensors and said test object at the time of obtaining said first signals doing said actual testing.