The accuracy of the temperature control instrument refers to the accuracy of the measurement results, also known as the accuracy or precision of the instrument; and the accuracy level is actually the accuracy level of the instrument; for example, a 0.2-level instrument, which represents a measurement error of ±0.2% ; The measurement accuracy of the temperature control instrument is a necessary condition for the control accuracy, but it is not a sufficient condition, because there are many factors that determine the temperature control accuracy, such as the PID mathematical model of the temperature control instrument, the PID parameter value, the operation efficiency of the single-chip microcomputer, the sensor The speed of response, the accuracy and response time of the actuator, etc. When customers choose the accuracy level of the instrument, the higher the accuracy level, the better (except for the measurement and testing institutions). Considering that the accuracy level of the current sensor in the market is generally between 0.2 and 0.5, the accuracy of the temperature control instrument is generally selected. 0.2 or Level 0.3 is sufficient.