A means of separating gaseous sulfuric acid from flue gas particles has been evaluated. Previous attempts to achieve this separation by filtration resulted in retention of the acid by the particulate buildup on the filter surface. By conducting a laboratory study of a prototype electrostatic precipitator, followed by actual flue gas sampling, it was found that the precipitator may eliminate the need for a filter without affecting the measurement results. It was also found that the precipitator could be used prior to a prototype acid monitor for the successful continual monitoring of H2S04in combustion gases.