Various single particle measuring techniques are briefly reviewed and the b
asic concepts of a new microsuperconducting quantum interference device tec
hnique are discussed. It allows measurements of the magnetization reversal
of single nanometer-sized particles at low temperature. The influence of th
e measuring technique on the system of interest is discussed. (C) 2000 Amer
ican Institute of Physics. [S0021-8979(00)36608-7].