Abstract
If the particle size is the important factor to be considered in case of droplet size spectrum then from our results, it can be said that Gauchard with 6 1/min, flow and Bird Asmastik with 95 1/min, are producing the particle size classes which can reach most easily the lower respiratory passage. The nebulizers which are producing droplets of a mass median diameter bigger than 10µ, send only an unpredictable portion of their liquid output into the lower respiratory system. Smaller particles are representing very little weight and carry only smalll quantities of liquid material unless present in vast majority in the aerosol. To recommend an ideal nebulizer is yet a long way to go but considering the very big quantitative influence of a few big droplets, a small mass median diameter (1–7 µ) is an important factor on the credit of any nebulizer.