Abstract:

MCU， temperature sensor， heating system， mixing system， keyboard and LCD are composed of the integrated smartmelting point apparatus, and its working principle is introduced. The hardware circuit and software program design are expounded, and experiments are carried out again and again. The results of experiments show the apparatus can get that the temperature control accuracy is ± 0.2 ℃, linear warming error is no more than 0.5%, and all criterions consistent with national pharmacopoeia standards. It can also prove that the configuration of hardware is simple, the software algorithms are scientific, and the instrument can achieve temperature control of lowcost highprecision. 

Key words: MCU, melting point apparatus, sensor, PID modulation, temperature control