when you are purchasing your welding rods you should request from your vendor the certificates of conformance (COC) at that time. keep all of your records in such a way that you can retrieve them for review. you may be tasked with keeping these records ( COC's , MT R's ) in a controlled , and secure manner no different than you do with your welding procedures , welders / operators certifications. but it all starts with requesting the documents at the start, well before you start any welding. the COC's should show all the test that have been performed.