1. What are other methods of moisture determination besides oven drying?

Question

2. During the drying of samples, the weight is considered constant when the last two weights are within ± 0.0003 grams. What is the reason for this?

For #1, here is a site for you to read.
(Broken Link Removed)

For #2, could it have something to do with the sensitivity of your balance?

I really don't know, but what I know is that the balance has an uncertainty of ±0.0002 g.