Evaluations of critical sampling parameters have been performed for primary sulfate measurement and characterization with a selective condensation method. It was found that filtration temperature and sampling flow rate were the critical parameters and t h a t sampling conducted using variations of the parameters would result in incomparable data. It was also found that a viable temperature controlled H2S04 collection device could replace the Goksoyr-Ross coil and alleviate H2S04 recovery and pressure drop problems which are common to the methodology.Increases in the use of sulfur-containing fuels for energy production have resulted in parallel increases in sulfur oxides emissions from power plants. While environmental concerns over these sulfur oxides formations were to surface much later, the corrosive effects of the oxides have been a persistent problem from the onset. Just as persistent have been the problems related to measuring the sulfur oxides quantitatively, particularly the higher oxides of sulfur trioxide (SO:,) and sulfuric acid (HzSO4). Depending on the nature of the fuel, boiler design, and firing conditions, the fuel sulfur is oxidized mainly to sulfur dioxide (Son). Subsequent to being oxidized to SO?, or by some alternate oxidation reaction route, from 1% to as high as 25% of the sulfur appears in the sulfate form ( I ) . Ordinarily, a large part of the sulfate exists as gaseous H2S04 or absorbed H&304 on ash particles. It is precisely this phenomenon, the potential of gaseous H2SO4 to interact with fuel gas particles, that has not only complicated corrosion difficulties, but has made the measurement of the sulfate species so difficult.In order to address the problems and parameters involved with acid formation in these combustion systems, extensive work was performed in Western Europe during the middle of this century. This work involved the study of acid formation as a function of excess air (2), sulfur content of the fuel (31, and effects of ash deposits ( 4 ) . For potential control approaches, the effects of fuel additives were also investigated (,5). Regardless of the objectives of the studies, difficulties were common and numerous when attempts were made to sample and quantitate the H$304 present in the flue gases.Basically, all of the measurement attempts involve the extractive sampling of the flue gas, followed by the attempted separation of the particulate related sulfate from the unassociated (or gaseous) H2S04. This separation attempt ordinarily involved either placing some type of porous plug in the inlet end of the sampling probe or passing the flue gas sample through a flat filtering pad following the probe. By assuming that all of the gas-phase HyS04 had passed the filter, the acid was then collected by an impinger train or by collecting the acid in aerosol form following its condensation. For most corrosion studies the filter was discarded, since the primary objective was measuring the HzS04 (to which the corrosion was attributed). The success of these studies was contingent upon ...