....I do not at this time own one or in fact even seen one.I was wondering if a first time user just dug everthing and record the numbers would this not give a real life numbers.As mentioned air tests are probably only general and can not include halo effects and diff soil conditions.But like I said never even seen a Explorer.Of course many things we do not find to do this but I'm talking about fairly common finds.While I'm saying my two cents why not just focus on the pulltab numbers easy to remember a few negative numbers and just dig all other readings,of course treasure and trash often have the same readings.But if not looking for nickels or gold,do you see part of my thought or is this farfetched hh ojm