Use this node at an exterior boundary to define the electrolyte mixture of a convective inlet stream. The electrolyte mixture may be defined either by using the same values as defined on an adjacent Initial Values domain node, or by specifying the Concentrations or Electrolyte component fractions on this node.

The boundary condition may be defined using either a Pointwise constraint or a Flux (Danckwerts) condition. The Pointwise constraint condition can sometimes be a more stable option, whereas the Flux (Danckwerts) may render more consistent results when specifying an upstream mixture composition when there are concentration gradients present in the electrolyte close to the boundary.