There is an ASTM standard for using a microwave for fuel moisture that works well. I have used it recently. ASTM E1358-97(2006) Standard Test Method for Determination of Moisture Content of Particulate Wood Fuels Using a Microwave Oven http://www.astm.org/cgi-bin/SoftCart.exe/DATABASE.CART/REDLINE_PAGES/E1358.h tm?E+mystore Tom Miles