eddy current calibration tube bundle specimen.dimensions: thickness based on customer requirements.description: pcn classification eddy current tube bundle specifications 13 tubes per bundle, 6 bundles are needed for training. 12 bundles for the exams, for a total of 18 bundles 3 no. cupro-nickel bundles for examinations 6 no. cupro-nickel bundles for training 3 no. aluminum brass bundles for training aluminum and brass 6no's bundles for tests.material