The paper describes experiments designed to demonstrate the effectiveness of a precharger--part of a novel electrostatic precipitator (ESP)--and to provide information needed to design a required downstream collector. The paper presents the first published data demonstrating the effect of the precharger on particle collection in an ESP. Graded penetration curves indicate that rapping reentrainment may be a problem. The penetration of large particles is higher than expected and is probably due to reentrainment. An optimized downstream collector should minimize the rapping reentrainment problem. The paper concludes that the precharger more than doubles the specific collector area of the ESP. Initial capital cost estimates indicate that the precharger will cost about a third to half the cost of one conventional electrical section. A conventional electrical section might increase the SCA of a small ESP, such as used for high sulfur coal, by as much as 33% and the SCA of a large ESP, such as used for low sulfur coal, by no more than 17%. Thus the cost effectiveness of the precharger appears to be excellent. Pilot and prototype scale field tests are planned to confirm the initial results.