You should be able to find the inspection criteria in the applicable welding code. Your contract specifications will tell you which code you are dealing with.
CHGuilford

I agree with Mr. Guilford's opinion. I'd just add that, in lack of any welding inspection criteria set forth in the contract documents, and as a steel tower is to be considered as structural steel, you can follow AWS D.1.1 Code.
Giovanni S. Crisi
Sao Paulo - Brazil