Sensors and actuators are the eyes, hands and feet of the computer control system. Without them, no monitoring and control can be performed. In actual use, due to the influence of dust, oil and harmful gases, the drift of the sensor means that the input is not Under the condition of change, the output of the sensor changes with time. There are two reasons for drift: one is the sensor's own structural parameters; the other is the surrounding environment (such as temperature, humidity, etc.). The most common drift is temperature drift, that is, changes in output caused by changes in ambient temperature. Temperature drift is mainly manifested as temperature zero drift and temperature sensitivity drift.
The sensor detects some external parameters, and then sends back some analog and digital signals. Due to some interference from the external environment, the signal sent back by the sensor is doped with some interference signals. Because the sensor wants to send the signal back, the signal needs to be amplified (Because the unprocessed signal is very small), but the interference signal is also amplified while the correct signal is amplified! Perhaps the interference signal was relatively large at the beginning, and after amplification, the interference signal has already occupied the main signal! The originally correct signal is completely changed to a signal dominated by interference signals. At this time, the signal transmitted by the sensor has changed, that is, drift! After a long period of time, aging will occur and the accuracy will decrease. The accuracy level of the humidity sensor should be judged in conjunction with its long-term stability.