text: how to calculate the geometric factor for the schlumberger array? geo electrical profiling can be done with fixed electrical electrodes and move only potential electrodes. i would like to know the formula i can use to calculate the geometric factor k for the different spacings the formula will be determined by several factors.  firstly you need to quantify the paralax of your electrodes when taken as a constant, then select your test apmere rate. this must be kept constant to give your results continuity.  the geometric factor can be determined either as a spacial value or a multi-dimensional cascade equation using the derivative of the base line through force as emitted by the polarised ion array under the radial effect of the ipnosis effect which can be detected using the omnidirectional fortence analyser (if available)  when these values are determined you must apply the correct formula which, as i have a standard keyboard which doesn't allow formulaic typing, i'm not going to tell you.