<GASP! Who? Me?> OK, one needs to understand several aspects of grounding, particularly where hazardous locations are concerned. Intrinsically-safe circuits do not necessarily require a low grounding-electrode resistance, but that would be an engineering call by the indicator producer and covered in installation instructions—which should be carefully understood and followed. The more important considerations are {ground} continuity of all conductive surfaces in the area where the work takes place, to keep potential difference as low as reasonably achievable.
As far as testers, you may want to contact AEMC or Megger sales reps and ask them to demo “fall-of-potential” or “three-point” and clamp-on test sets. They all have their positive characteristics, as well as limitations.
The fill material I’m familiar with is
“Lynconite”
http://www.lyncole.com/html/Misc.asp#salt “GEM”
http://www.erico.com/erico_public/product/GEM.asp That’s the short version. Don’t hesitate to follow up with any other questions.
