An arc suppression system for plasma processing comprising at least one sensor coupled to the plasma processing system, and a controller coupled to the at least one sensor. The controller provides at least one algorithm for determining a state of plasma in contact with a substrate using at least one signal generated from the at least one sensor and controlling a plasma processing system in order to suppress an arcing event. When voltage differences between sensors exceed a target difference, the plasma processing system is determined to be susceptible to arcing. During this condition, an operator is notified, and decision can be made to either continue processing, modify processing, or discontinue processing.