COMPARISON OF 2 MEINHARD NEBULIZERS OPERATING AT THE SAME ARGON FLOW BUT DIFFERENT PRESSURES

Two Meinhard nebulizers were designed to operate at 0.8 l/min, one with a pressure of 31 psig and the other 46 psig. Both nebulizers had identical liquid uptake rates of 2 ml/min, uptake tube cross-sectional areas (A1), and uptake tube wall thicknesses. Values for W(tot) and S(tot) were virtually identical for each nebulizer. The 31 psig nebulizer produced a larger volume of particles in the 1.1-2.5 mum range than the 46 psig model even though the mean tertiary D3,2 were 2.46 and 2.14 mum respectively. The 46 psig nebulizer produced a larger volume of particles < 1.1 mum. Inductively coupled plasma emission intensities for high excitation potential lines were enhanced at all observation heights and liquid flow rates with the 46 psig nebulizer. The effects of changing gas orifice area and other physical parameters of concentric nebulizers are discussed.