Aries, in addition to using my hot box, I also use a hygrometer to monitor the humidity in the hot box. You can get a hygrometer/thermometer from Lowes or Home Depot for about $10.00. Also download a Wood Equilibrium Moisture Content Table and tape it to your hotbox. The chart will tell you the MC of the wood at a particular temperature and humidity level. Sometimes, I have to add trays of water so the wood doesn't get too dry. A kitchen scale like wizardgoat suggested will tell you when the MC equalizes at a specific temperature and humidity level. It all works together to give you good accurate information when working with hickory.
Hope this is helpful. Works well for me.