Task: Translation
Input (Spanish): The present invention relates to apparatus for a tool for investigating the wall of a borehole in a geological formation, the apparatus comprising: a non conductive pad (3) having an inside face and an outside face for pressing against the wall; a set of measurement electrodes (6) mounted on the outside face of the pad and means for measuring the potential difference between two measurement electrodes; and both a source electrode (4) adapted to inject current into the geological formation and a return electrode (5), the set of measurement electrodes (6) being situated between the source electrode (4) and the return electrode (5) for the current; the apparatus being characterized in that the pad comprises an electrically conductive portion (8) covering the entire measurement electrode zone and electrically insulated from the measurement electrodes.
Output (English): La presente invencion se refiere a un aparato para una herramienta para investigar la pared de una perforacion en una formacion geologica, el aparato comprende: un cojin no conductor (3) que tiene una cara interior y una cara exterior para prensar contra la pared; un conjunto de electrodos de medicion (6) montado en la cara externa del cojin y medios para medir la diferencia potencial entre los dos electrodos de medicion; y tanto un electrodo fuente (4) adaptado para inyectar corriente dentro de la formacion geologica como un electrodo de retorno (5), el conjunto de electrodos de medicion (6) esta situado entre el electrodo fuente (4) y el electrodo de retorno (5) para la corriente; el aparato se caracteriza porque el cojin comprende una porcion electricamente conductora (8) que cubre toda la zona del electrodo de medicion y electricamente aislado de los electrodos de medicion.