The CSK-IA test block is an improved version of the IIW test block, and its main uses include: 1. Using the R100mm curved surface to measure the incident point and leading edge length of the oblique probe; 2. Use 50 and 1.5mm circular holes to measure the refractive angle of the angle probe; 3. Use the right angled edge of the test block to measure the deviation of the sound beam axis of the oblique probe; 4. Use a 25mm thickness to measure the horizontal linearity, vertical linearity, and dynamic range of the flaw detector; Adjust the longitudinal wave detection range and scanning speed using a thickness of 25mm; 6. Use R50 and R100mm curved surfaces to adjust the transverse wave detection range and scanning speed; Measure the resolution of the angle probe using three step holes of 50, 44, and 40mm.