Abstract: A device for evaluating the internal dielectric behavior of a structure with a capacitive sensor and a method of using such a device. The device allows a user to measure the internal dielectric behavior of a wooden structure and to derive a density profile for that structure from the determined dielectric behavior. The condition profile allows the user of the device to locate regions of altered condition within a structure to determine whether that structure has suffered from internal decay, pre-rot, rot, or other forms of damage. The minimally-invasive device avoids the need for more damaging and destructive modes of analysis of the wooden structure and is able to provide accurate and repeatable measurements of the structure's density and moisture content, obviating the need for more complex and expensive equipment and techniques.