Uncertainty Evaluation on Measurement by MP30 Ferrite Content Detector

The δ-ferrite in weld joint of austenitic stainless steel has a impact on strength and toughness, corrosion-resistant and welding qualities of weld joint. So δ-ferrite content was usually controlled by using ferrite content detector. The evaluation methods of uncertainty in measurement by MP30 ferrite content detector were mainly discussed. The results showed that the synthetic uncertainty uc was 0.47 FN, the degree of freedom νc was 26, and the expanded uncertainty U is 0.94 FN.