A new version of laminar flow diffusion chamber was developed for unary homogeneous nucleation from vapor to liquid studies. The developed laminar flow diffusion chamber can quantitatively measure nucleation rates as a function of saturation ratio and temperature. A numerical model was developed for calculations of temperature and saturation ratio profiles inside the laminar flow diffusion chamber. Several experiments were made to ensure the proper and reliable operation of the device and the numerical model. Nucleation rates of n-hexanol were measured using helium as a carrier gas from 265.0 to 295.0 K. The measured nucleation rate range was from 10(3) to 10(7) cm(-3) s(-1). Temperature and saturation ratio dependencies were compared to the classical nucleation theory. The saturation ratio dependency was well predicted by the theory. Results were compared to the measurements made by others. They were in reasonable agreement at the lower end of the temperature range of this study. The carrier gas effect was also investigated using argon as another carrier gas, The nucleation was stronger when argon was used as a carrier gas.