Figure F13. Diagram showing the DSI tool configuration (after Schlumberger, 1995). Distances are given in centimeters. The DSI tool is divided into a transmitter sonde, a receiver sonde, and an acquisition cartridge. The transmitter sonde drives one dual-frequency (14 and 1 kHz) monopole transmitter and two pair of dipole (2.2 kHz) transmitters. The receiver sonde houses an array of eight receiver groups with 15-cm spacing, each consisting of four orthogonal elements that are aligned with the dipole transmitters. The output from these 32 individual elements are differenced or summed appropriately to produce in-line and cross-line dipole signals or monopole-equivalent (compressional and Stoneley) waveforms.