Hi, I hope I can get some ideas on this,

The Moisture Content seems to vary between the original and new plywood.
The readings have been consistent over the last few weeks.

This is in Plantation Florida, 2nd floor of house. The house was built in 1992,
Using mini-LIGNO DX/C to measure moisture
Temp= 80, RH=49

The original subfloor has an MC of 15 while the new plywood has an MC of 11. The new has had plenty of time to acclimate. Not sure what to think. Below are the various readings I took to make sense of it.,

I used the species chart that came with my meter and selected SPF = 12.
For the Kempas and Pine, I changed per species.
The original plywood is 2x4x3/4" T&G, the plywood reading in each room was consistent, averaging 15. However an area where I replaced a sheet about 6 months ago with a 4x8x3/4” TG, I get a reading of 11. The old sheet I replaced, which I still have measures 16, and a 2’x2’ panel that has been out of the floor for about 6 months measures 15.

A separate 4x8x3/4” measured 10.5, a 4x8x ½” sheet measured 11, they have both. been in the house a year and are new.
2 different Kempas samples read 8.5, 8.9, pine shelving that is built into the house in each room ranges 10-11.

All the new plywood is Georgia Pacific EXPOSURE 1 from home-depot.
The printing on the old sheets are not too clear but I can make out EXPOSURE 1 and FLOOR.

Any ideas?
thanks,
Mike