What kind of system certificate has high gold content is relative, and the key depends on what kind of certificate you need at work. If your job is to use the certificate of mechanical society, it is useless for you to take other exams.

If you are not engaged in related work now and only want to take the NDT certificate, it is recommended to take the special equipment, ships or power systems of the Quality Supervision Bureau. Personally, I feel that these are used more. -NDT personnel