However, in practical applications, customers often find that the temperature control of the water bath constant temperature magnetic stirrer is inaccurate. This can be manifested as the sample temperature surging during the rapid heating process, exceeding the set control temperature, or the sample temperature fluctuating high and low throughout the entire temperature control process, resulting in a large temperature control deviation, or the actual temperature not reaching the set temperature.

Experience has shown that the temperature control accuracy that a sample medium can achieve depends not only on hardware factors such as instrument performance, but also on factors such as disk temperature, container material, solution capacity, solution heat capacity, stirring speed, ambient temperature, and airflow.

PID stands for Proportional Integral Derivative, which is the three control conditions for generating control signals based on erroneous signals. In some applications, only one or two conditions need to be applied to generate appropriate system control. P (proportional) control can provide stable processing temperature, but there may be errors between the set temperature and the actual temperature. I (integral) controls the steady-state error of the display system and eliminates the error between the set temperature and the actual measured temperature. For many applications, P+I control can already meet the application requirements with its good stability and accuracy in reaching the set temperature. D (differential) control is commonly used for processing rapidly changing process outputs.

Stop heating a liquid sample after reaching the set temperature. If the sample temperature gradually decreases, PI control will immediately take effect and slightly heat the sample. It seems that the temperature of the sample will not experience any fluctuations, but in reality, the controller can sense these slight temperature fluctuations. If you add ice water to the sample, the temperature change will be very rapid. D control will respond to these rapid temperatures until the sample temperature reaches the set value. Therefore, there will not be significant deviation in the set temperature of the sample, and the final fine-tuning will be achieved through PI control. It can be seen that rapid and precise temperature control can be achieved by adjusting the three control conditions of P, I, and D.