The Dec Scanner is a non-destructive impedance moisture detector (scanner) designed to detect and assess moisture conditions in roofing and waterproofing systems. The Dec Scanner has 3 ranges of sensitivity to allow inspection of a variety of roof types and depths, and is equipped to detect moisture in most roofing and waterproofing systems.

The Dec Scanner is a battery-powered electronic instrument that generates a low-frequency electronic signal. This signal is transmitted into the inspected material through one of the two built-in electrodes located at the bottom of the instrument. The other electrode receives the transmitted signal from the inspected material. The strength of this signal varies in proportion to the amount of moisture in the material. The Dec Scanner determines the strength of the current and converts it into a comparative moisture value. By moving the Dec Scanner in regular movements along an overlay surface, a continuous reading is obtained and any area containing moisture can be readily identified. 

This system allows investigations to be carried out even with very high thicknesses (250 mm).