Similarly for the eddy current probe, the probe is inserted into the tube and entire tube is inspected one coil with or diameter at a time. This is a very time consuming approach not only from the actual time required for inspection but also because occasionally the probes get stuck in the tube or cannot be completely inserted into the tube. The magnetostrictive sensor (MsS) "tube gun" probe can inspect the entire length of the tube from one location using guided waves. The tube gun probe allows inspection of nonferromagnetic tubing, such as inconel, stainless steel, brass, and copper using guided waves generated in the tube gun and mechanically coupled into the nonferromagnetic material. The probe is inserted approximately 6 to 8 inches into the tube at one end. The technique is sensitive to overall wall thinning (greater than 5%) and cross sectional, localised defects (greater than 2% of the cross sectional area). The technology and results obtained in laboratory and field evaluations will be discussed.