A system for dispensing and continuously measuring the flow of solid particles into a hot high‐pressure gas flow for times up to 1 h is described. A differential pressure across an orifice is used to force the particle flow. A strain gauge load cell is used to continuously sense the weight of the container from which the particles are being dispensed. Calibration results are included for flows of 100‐&mgr;m‐diam glass spheres through several orifices at rates from 1 to 15 g/s.