This paper describes the operation of a pressure scanner, specifically the Scanivalve DSA 3218 device, when used to characterize the pressure evolution along the expansion process of an organic vapor. The working fluid Hexamethyldisiloxane (MM) is expanded in the De Laval nozzle of the ORCHID facility for various inlet thermodynamic conditions: 220  \(^\circ \text {C}\) and 4bar, 220  \(^\circ \text {C}\) and 10.8bar, and 244  \(^\circ \text {C}\) and 13.3bar. Pressure is measured along the nozzle walls using 16 pressure taps. Each of them is connected to a pressure line, which may be affected by varying rates of working fluid condensation, despite all pressure lines being purged with nitrogen before starting data acquisition. Fluid condensation increases the time response of the measurement system and potentially impacts the accuracy of the measurements. Repeated tests show that the steady-state values recorded by the pressure scanner once hydrostatic equilibrium is reached in the lines, are marginally affected by the amount of condensing fluid and the adopted purging strategy. This is observed for all pressure lines, including those connected to the taps placed before the nozzle throat, where substantial condensate accumulation occurs during testing as the thermodynamic state of the vapour is closer to the saturation curve. The experimental campaign documented in this paper paves the way for further refinement of the pressure scanner measurement procedure for non-ideal vapour flows and its application to the characterization of expansion processes in small power capacity ORC turbines.