Methods using a probe apparatus configured to measure a set of electrical characteristics in a plasma include providing a chamber wall including at least a set of plasma chamber surfaces configured to be exposed to a plasma, the plasma having a set of electrical characteristics. The method includes installing a collection disk structure configured to be exposed to the plasma, wherein the collection disk structure having at least a body disposed within the chamber wall and a collection disk structure surface that is either coplanar or recessed with at least one of the set of plasma chamber surfaces and providing a conductive path configured to transmit the set of electrical characteristics from the collection disk structure to a set of transducers. The method may include coupling a thermal grounding element with the conductive path for providing thermal grounding to at least the conductive path and may alternatively or additionally include disposing an insulation barrier configured to substantially electrically separate at least one of the collection disk and the conductive path.