It sounds like you are looking for a high-quality reference document or technical paper regarding BS EN 970 (the now-superseded standard for visual inspection of fusion welds) and specifically want a PDF version.
However, there is an important technical correction to make first:
BS EN 970:1997 was officially withdrawn and replaced by BS EN ISO 17637:2011 (Non-destructive testing of welds — Visual testing of fusion-welded joints). Therefore, any "best paper" today should ideally refer to the current standard or a comparative study.
Here is the best way to get what you need, categorized by "best paper type": bs en 970 visual inspectionpdf best
The most authoritative document is BS EN ISO 17637:2016 (the latest update).
Since a direct PDF of the standard is copyrighted, look for these papers/guides from reputable training bodies:
Search query for free PDFs:
"BS EN 970" visual inspection training notes filetype:pdf
or
"ISO 17637" comparison to EN 970 filetype:pdf It sounds like you are looking for a
The objective is to verify that all conditions are suitable for welding. Key checks include:
BS EN 970 applies to the visual inspection of fusion welds in metallic materials. It details how the inspection should be performed, the equipment required, and the necessary skills of the inspector. It does not, however, define acceptance criteria (what constitutes a "pass" or "fail") on its own.
Do not use BS EN 970 alone – it was confirmed withdrawn in 2016. Instead, download: Title: Non-destructive testing of welds – Visual testing
ISO 17637:2016 – Non-destructive testing of welds – Visual testing of fusion-welded joints
It supersedes BS EN 970 and includes all the same content plus modern updates on digital imaging and lighting.