We are developing an experimental approach to investigation of the properties of not fully stable fluids based on the procedure of controlled pulse heating of a thin wire probe using pulse lengths from 1 to 10 ms. We shall use the term "not fully stable" to refer to fluids that lose their stability in the course of heating (superheated liquids and thermally unstable ones), as well as to initially unstable systems (nanofluids and supercritical ones). In this paper, the peculiarities of the technique and the device operation are discussed. The applicability of the approach is illustrated by demonstration experiments with not fully stable fluids using the constant heating power mode. (C) 2013 Elsevier B.V. All rights reserved.