Abstract: This invention relates to apparatus for accurately determining the characteristics of turbo-powered simulators. The apparatus provides for the determination of the air flow through the turbine of the simulator, the air flow through the fan section, and the thrust produced, all with high accuracy. The data thus accumulated, together with the data on temperatures and pressures both inside and outside the simulated engine, enable the engineer to determine other desired characteristics. The apparatus is free of certain disadvantages of conventional equipment in that it substantially eliminates tare forces in thrust measurement, it eliminates the necessity of accounting for inlet momentum, it minimizes distortion of inlet flow, and it enables simple and accurate measurement of the air flow through the engine simulator.