Humidor charging question

[OldSquidRoy]

I have a couple of them and they work....and I keep a few flat sheets of cedar and one Boveda pak....works great!

I've got a few questions on the jars:

1) How thick do you cut the cedar for the base plate, and does it have to be charged like a regular humidor?
2) How would I install a hygrometer? Just charge it then drop it in the jar - on top of the cigars... or can it mount somehow on the inside of the lid?