I do not personally know of any training centers in California, but I live near Chicago. Have you checked ASNT's website and looked under learning for educational institutes? They have a list from colleges to industrial/commercial training centers. I have seen several training centers listed in California, Oregon and Washington. For a good introduction to basic/Level I UT, check out: http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/Introduction/description.htm