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Fig. 2. Raw and corrected conductivity logs from borehole R-8. The instrument was calibrated before the logging run. Steady decrease in signal with time is seen in comparison of data from downward and upward instrument paths (2a). The rate of decrease in signal is systematic and can be fit by a second-order function (d = depth in feet) with R2 of 0.84 (2b). Correction functions can be applied to the signal values at each depth in both downward and upward paths (2c) to generate corrected curves that account for instrument drift (Fig. 2d).
