Precision Temperature Control Max. 250?, ±0.2? accuracy, ±1.0? uniformity Digital PID Controller enable 0.1? resolution Equipped with wait-off timer, alarm, auto-tuning and in built temperature calibration function. Dual Heating System Two fans and heaters on the upper and lower part of chamber eliminate temperature difference from top to bottom. Aero-dynamic design of air circulation from heating chamber located in side wall by horizontal air flow achieve superior temperature uniformity