A fluid exchanging system and method for use in exchanging fluids in insulating glass units (IGUs). The fluid exchanging system includes an articulating arm having a plurality of members and arms to allow movement about multiple axes defined by the articulating arm, an optical sensor system, coupled to the articulating arm, for identifying an opening in a spacer frame of an IGU, and a fluid exchanging apparatus releasably couplable to the articulating arm. The fluid exchanging apparatus also includes a fluid exchanging head for evacuating atmospheric air from the IGU and dispensing fluid into the IGU.