Electrical testing safety.PDF
Interesting read, thanks for posting.
From my experience, I would like to see correct identification of the apparatus and use of proving units added into the article.
As a further point, 2 pole voltage testers should not be fused under the IEC standard, but should instead have a high input impedance. Under certain fault conditions, a 2 pole tester can also fail to detect a voltage, where a non-contact indicator would still work.