I believe the Leafs used for the SAP Readings should be taken from the middle,
Not New leafs (still pulling nutrients) Not Older leafs, these have less mosture
and give a higher reading.
I Have been told to take newest fully mature leaves, this is usually somewhere
in the middle area closer to the top.
At least this is how I understand it, could be wrong but think this to be correct
Yes this seemed to make a difference. The more healthy leaf from the upper canopy had a higher reading