Construction and operation of the electrodynamic levitation trap which can
be operated in a passive and an active mode is described. This combination
together with variable electrode geometry simplifies the trap's design and
simultaneously gives more flexibility with respect to different kinds of me
asurements. Sample measurements of mechanocaloric effect caused by nonunifo
rm heating of a single levitated particle are presented and discussed. (C)
1999 American Institute of Physics. [S0034-6748(99)03711-9].