Ground balance and Fe O bar

How are these tied together yet different.
I ask because i live in Mass and think my soil is on the mild side but after a Fast Grab
the numbers tend to be in the mid 70s. In the F75 hand book it says 75 - 95 is black iron minerials
but yet my Fe O meter rarly go above the lowest bars on the scale .I also used other detectors that the ground balance
is low on the ground balance adjustment . Thanks Mike



Edited 1 time(s). Last edit at 06/19/2010 03:19AM by gman.

HELP! I've answered this a few times in a few other threads. I'm short on time to find them.

Found answer by HumblePie in thread on
[ How to determine if you soil is hot? ]



Edited 1 time(s). Last edit at 06/19/2010 04:11PM by gman.