I'll try to contribute something as I've tested tops for many years now.
Here are some photos of my test fixture. This fixture isolates each axis as it spans the entire length/width of the top giving me a sperate number for each axis.
I test unjoined tops around .150-.160 and I use this primarily as a sorting guide. I look at youngs modulus in each axis and the ratio between the two. I also look at the desity of the wood and it's relationship to it stiffness. Stiffness tracks density rather nicely BTW, of course there are exceptions to that. I use standard engineering formulas to find the modulus of each axis. Here's a link to a good paper on wood testing by Charles Wood a violin maker that really got me thinking about this years ago.
http://www.scavm.com/Woods.htmHe has all the formulas written out in the paper so you can get them there, it's easier than me retyping them and it's a good paper.
I've also attached a PDF of my spread sheet which shows the things I'm tracking if that helps anyone.
I also deflect my braced tops in multiple locations and track that also, the last 2 photos show that.
I don't know how coherent this is, but I hope it helps some.
Attachment:
test jig 4.jpg
Attachment:
test jig 2.jpg
Attachment:
test jig 3.jpg
Attachment:
test jig 1.jpg
Attachment:
top deflection sample.pdf
Attachment:
tapping-frame-2.jpg
Attachment:
top-dial-indicator-jig-2.jpg
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