DL-EPR test vs PD
A comparison between the sensitivity of the two techniques in the estimation of the increase of intergranular corrosion is made through the evaluation of the percentage of increase of the characteristic values obtainable with the two kind of measurement:
DOS increase (%) = 100* (X-X0/X0)
where X is ir/ia or i0.2 for the DL-EPR and the PD measurements, respectively, and the 0 subscript indicates the characteristic value for the as received sample.