A previously reported computer-based, local heat-transfer sensor system was utilized to determine process-side heat-transfer coefficients associated with mixing with a high-efficiency impeller. Each impeller (of different diameters) was evaluated to determine its effects on the mixing parameters of the tank. A 0.38-m vessel with a liquid depth of 0.46 m was used. The off-bottom clearance of the impeller was T/6 (6.35 cm). Impeller speed was varied to provide a range of Reynolds numbers. The exponents for the normally accepted empirical heat-transfer equation were examined for each component.