  A simple approach to describe the levitation force measurements on
melt-processed HTS bulks was developed. A couple of methods to determine the
critical current density $J_c$ were introduced. The averaged $ab$-plane $J_c$
values for the field parallel to this plane were determined. The first and
second levitation force hysteresis loops calculated with these $J_c$ values
coincide remarkably well with the experimental data.
