In many high temperature environments, the degradation of the coating is often a result of a synergistic effect of several factors; the attack of the corrosive gases, deposition of by-products and erosion or abrasion induced by impact of the flying particles. Proper selection of a coating for such environment requires that tests be conducted “in service” or with an apparatus which can closely emulate the service conditions. A simulated environment erosion test platform employing a control chamber, a modified HVOF gun, a high speed camera, and a DPV/CPS 2000 particle flight diagnostic sensor is presented. This robust equipment can vary angles of impingement from 0-90 degrees, erodent velocities up to 250 m/s, and temperatures exceeding 1000 C. The particle velocity, flow rates and temperatures are directly measured in contrast to estimates typically reported in the literature. A thorough statistical study of the erosion characteristics of three coatings systems (designed for room temperature, high temperature and a functionally gradient coating) has been conducted. Also, erodent size, erodent shape and coating surface finish were varied in these tests. Finally, detailed microstructure studies, using an SEM, of the coatings before and after the test are presented to determine how the coating microstructure and hardness affects erosion rates. It is believed that the quantitative characterization of test parameters would greatly assist the designer in choosing and developing the appropriate erosion resistant coatings for their application.