What is “warm drift”?
Under the interference of external factors, the output of the sensor will usually change unnecessarily, which is independent of the input. This kind of change is called “temperature drift”, and the drift is mainly caused by the sensitivity element of the measurement system, which is usually vulnerable to the interference of external temperature, humidity, electromagnetic interference and the sensor conditioning circuit. The temperature drift to be discussed today mainly refers to the changes of semiconductor device parameters caused by temperature changes.
Why should the pressure sensor be temperature compensated
For the diffused silicon pressure sensor, the change of the diffused silicon resistance caused by the temperature change at the measuring site is almost the same order of magnitude as the change of the diffused silicon resistance when measuring the strain, which brings a certain temperature drift error to the measurement test. The introduction of temperature error directly affects the accuracy of the measurement results, specifically: the output voltage of the static working point of the pressure sensor fluctuates due to the temperature change of the measured medium. Therefore, temperature compensation is required.
How to control the phenomenon of “temperature drift”?
For the temperature drift of the pressure sensor, it is necessary to select an appropriate compensation method to control the temperature drift based on specific reasons. The commonly used methods are mainly divided into hardware compensation method and software compensation method. The microphone sensor uses the hardware compensation method to balance the zero drift caused by the mismatch of the initial values of the four diffused silicon resistors and the temperature drift that changes with the temperature by series and parallel connection of a certain resistance value to the corresponding bridge arms among the four resistors that make up the Wheatstone bridge.
Post time: Nov-17-2022