by other metal ions from the oil that change the signature of the output signal of particular interest would be the electrical signature of iron or lead present in the oil indicating engine wear due to iron or lead entering the oil from the engine components using two differently treated sensors both immersed in the engine oil such as one treated with sodium and the other treated with iron the output signals electrical signatures of the two sensors are compared for instance by a microprocessor a sensor of this type would appear to be similar to that of fig4 initially the signatures of the two sensors would be different when iron contamination of the oil occurs the sodium ion in the resin beads in the first sensor is displaced by the iron ion and the signatures from the two sensors would then be the same indicating oil degradation the engine iron copper lead zinc etc present in the oil is oxidized from a metal state to an ionic state by a compatible charged group and encounters the sodium on the resin beads and displaces it a zero output from the comparator see fig4 indicates contamination for instance by copper zinc lead or iron and excessive engine wear one could even determine where the particular wear is occurring in terms of engine components depending on e g the known lead concentration in each various engine component also in accordance with the present invention a multi chamber sensor determines oil level typically to determine a low oil condition in this case the entire sensor assembly 90 as shown in fig5 is located in the engine oil pan 98 and arranged vertically the indicated oil levels are e g the oil pan 98 is.