Bezugsknoten

Bezugsknoten, literally “reference node,” is a designated node in a network, graph, or circuit that serves as the baseline against which other quantities are defined. The node provides a fixed reference point for measurements, potentials, distances, or labels, allowing a unique numerical description of the remaining nodes. In many fields the choice of Bezugsknoten is arbitrary but must be fixed for a given analysis.

In circuit theory and electrical engineering, the Bezugsknoten is commonly referred to as the ground or reference node. It is assigned a reference potential, typically zero volts, and all other node voltages are measured relative to it. Selecting a Bezugsknoten simplifies equation formulation (for example, in nodal analysis) by reducing the number of independent variables. The choice of reference does not alter the network’s physical behavior; it only changes the numerical values of potentials.

In graph algorithms and network analysis, a Bezugsknoten may be chosen as a root in tree representations or as an origin for distance and label calculations (for example, in breadth-first search traversals, shortest-path computations, or coordinate embeddings). The concept is analogous to root nodes in trees or to reference frames in geometry.

Limitations and notes: Different analyses may select different Bezugsknoten, so the resulting numerical values depend on the chosen reference, even though the underlying topology remains the same. Related terms in German texts include Bezugspunkt or Referenzknoten, often used synonymously.

See also: Ground, Reference frame, Root node, Nodal analysis, Slack bus.