Back To Products Page WADI - ELECTROMAGNETIC VLF WADI, for water and minerals WADI finds structures where useful quantities of underground water may be trapped in rock fractures and cavities, thus enabling drillers to select the most promising sites for their wells. It also reacts to other types of high-conductivity anomalies such as certain orebodies, electrical cables, metallic pipes, buried waste, clay-filled sinkholes and cavities. The VLF Principle. WADI utilizes the magnetic components of the electromagnetic field generated by long-distance radio transmitters in the VLF (Very Low Frequency) band. Conductive structures on the surface or underground, even when covered with thick overburden, affect locally the direction and strength of the field generated by the transmitted radio signal. WADI measures the radio signal distortion and presents the result directly on a display screen. When the surveyor passes over a conductive structure, WADI displays a peak on a normally straight line. When you press a key, WADI will indicate the depth to the conductive zone and its dip. The depth capacity of WADI is normally about 50 to 60 m. Built-in data storage for 4000 survey stations is included. FREQUENCY LIST:   Vlf Frequency List   Download the VLF Frequency List in ACROBAT PDF file format. To read the file you need the free Adobe Acrobat Reader program.   Back To Products Page ABEM Instrument AB | Löfströms allé 1 | S-172 66 Sundbyberg | Sweden Phone: +46 8 564 88 300 | Email: sales@abem.se