The phase or associated amplitude analysis of a sequence of images is improved by, first, providing quantifications in response to the phase or amplitude information. The invention allows to avoid re-treatment of large quantities of material, and provides a clear separation between contaminated and uncontaminated parts of the installation. When urine bridges the gap between spaced electrical conductors the presence of the urine is electronically detected and a signal is emitted that activates an audible andor visual alarm device to alert the animal owner of a spraying occurrence. The incremented value is compared by a Comparator circuit with a pre-determined threshold value \u2018n\u2019. The rod-like structure or pawl provides superior structural rigidity for the bench when restricted with rear shims to rotation into the ratchet slots at an angle between less than about 45 degrees and greater than about 10 degrees.