Progress being made to develop improved laboratory methods for analyzing coal and fly ash samples as they may affect electrostatic precipitator design and operation was reported in four papers presented at the IEEE/ASME Joint Power Generation Conference September 20, 1977 meeting in Long Beach, CA. In a progress report by the IEEE Task Force P-548, a review is made of fly ash laboratory resistivity measurements, and the problems associated with sizing precipitators based on coal sample analyses. Â second paper describes Australian experience in determining repeatability and 95% confidence intervals of laboratory fly ash resistivity measurements using three Australian and three American sources of fly ash samples. The authors demonstrate that a high level of repeatability can be obtained. A third paper presents a comparative evaluation of three design configurations of laboratory fly ash resistivity measuring cells. A parallel plate cell with guard ring geometry is recommended although all cell designs gave similar results. The fourth paper presents a progress report on the development of a small furnace to produce fly ash similar in character to fly ash from full scale boiler installations. Reasonable progress is reported.