The purpose of this research work was to employ the optical technique of real time holographic interferometry to measure local mass transfer rates from a flat surface, coated with silicone rubber polymer swollen with a liquid swelling agent of known physical properties, into an impinging air stream in various specified flow conditions. A proprietary holocamera was to be employed to make the required holograms during the work. The first part of the experimental work was concerned with the clarification of the situation regarding the vapour pressure of a widely used swelling agent (ethyl salicylate). Paterson et al [28] have claimed that previous vapour pressure values of ethyl salicylate measured and reported by Kapur and Macleod [27] and subsequently widely used by other workers, are in fact higher by about 25&37 than the true values as carefully redetermined by them. On the other hand the vapour pressure values of Kapur and Macleod give mass transfer coefficients in impinging laminar jet experiments in close agreement with theoretical expectation. Laminar impinging air-jet experiments were to be carried out to calibrate the technique of measurement; mass transfer rates of chemically different materials from a flat polymer-coated surface into a submerged impinging isothermal air-jet were to be measured, and the results were to be used to test the related theory. Finally, it was intended to extend the mass transfer measurements to turbulent air jets, using a suitable swelling agent. Laminar mass transfer experiments were carried out at room temperature for two nozzles; a plain tube and a contoured nozzle, using three suitable swelling agents (ethyl salicylate, 1-methyl naphthalene and n-tetradecane) under various dynamic conditions involving variation of nozzle-to place spacing in the range z/d = 0.26-20.0 and Reynolds number in the range Re = 700-1,810.