A contaminant detection system comprising: a sensor (12, 51) configured to respond at a plurality of voltages including a first voltage and a second voltage; wherein the system is configured such that the plurality of voltages are provided to the sensor in a continuous, multiple sweeping fashion over a range of voltages that includes the first and second voltages; wherein the first and second voltages are different; a controller (11, 72) configured to receive a resistance response from the sensor; and a lookup table created of contaminants, contaminant concentrations, contaminant sources, resistance response and/or applied voltage; wherein at the first voltage, the sensor can provide a first resistance response to the controller as the plurality of voltages continue to sweep up and down over the range of voltages; and at the second voltage, the sensor can provide a second resistance response to the controller as the plurality of voltages continue to sweep up and down over the range of voltages; wherein the first and second resistance responses are different from one another; and wherein the first and second resistance response are both determined relative to a resistance baseline; and wherein the resistance response is configured to return to the resistance baseline following the first resistance response, the second resistance response, or following both the first resistance response and the second resistance response; and wherein the controller is configured to compare the resistance response from the sensor to the resistance responses in the lookup table to identify a contaminant and in turn, a contaminant source; wherein when the first resistance response meets or exceeds a first threshold, a presence of a first contaminant is indicated, and the controller is further configured to initiate corrective action based on the source of the first contaminant, and when the second resistance response meets or exceeds a second threshold, a presence of a second contaminant is indicated, and the controller is further configured to initiate corrective action based on the source of the second contaminant; wherein the first and second contaminants are different. a sensor (12, 51) configured to respond at a plurality of voltages including a first voltage and a second voltage; wherein the system is configured such that the plurality of voltages are provided to the sensor in a continuous, multiple sweeping fashion over a range of voltages that includes the first and second voltages; wherein the first and second voltages are different; a controller (11, 72) configured to receive a resistance response from the sensor; and a lookup table created of contaminants, contaminant concentrations, contaminant sources, resistance response and/or applied voltage; wherein at the first voltage, the sensor can provide a first resistance response to the controller as the plurality of voltages continue to sweep up and down over the range of voltages; and at the second voltage, the sensor can provide a second resistance response to the controller as the plurality of voltages continue to sweep up and down over the range of voltages; wherein the first and second resistance responses are different from one another; and wherein the first and second resistance response are both determined relative to a resistance baseline; and wherein the resistance response is configured to return to the resistance baseline following the first resistance response, the second resistance response, or following both the first resistance response and the second resistance response; and at the first voltage, the sensor can provide a first resistance response to the controller as the plurality of voltages continue to sweep up and down over the range of voltages; and at the second voltage, the sensor can provide a second resistance response to the controller as the plurality of voltages continue to sweep up and down over the range of voltages; wherein the first and second resistance responses are different from one another; and wherein the first and second resistance response are both determined relative to a resistance baseline; and wherein the resistance response is configured to return to the resistance baseline following the first resistance response, the second resistance response, or following both the first resistance response and the second resistance response; and wherein the controller is configured to compare the resistance response from the sensor to the resistance responses in the lookup table to identify a contaminant and in turn, a contaminant source; wherein when the first resistance response meets or exceeds a first threshold, a presence of a first contaminant is indicated, and the controller is further configured to initiate corrective action based on the source of the first contaminant, and when the second resistance response meets or exceeds a second threshold, a presence of a second contaminant is indicated, and the controller is further configured to initiate corrective action based on the source of the second contaminant; wherein the first and second contaminants are different.