The acausal bond graph of system Weir is
displayed in Figure 4.3 (on page ) and its label
file is listed in Section 4.1.4 (on page ).
The subsystems are listed in Section 4.1.4 (on page ).
The weir is modelled by an ISW component in series with an
R component. Physicaly, the former represents the inertia of
the fluid together with the switching effect of the weir; the latter
represents the flow resistance.
The switching logic is on if the level on either side of the weir
reaches the level of the weir.