What is "temperature drift"?

Under the interference of external factors, the output of the sensor will usually change unnecessarily, which is not related to the input. This type of change is called "temperature drift", and the drift is mainly caused by the sensitivity components of the measurement system. It is susceptible to interference from external temperature, humidity, electromagnetic interference and sensor conditioning circuits. The temperature drift discussed today mainly refers to the changes in the parameters of semiconductor devices caused by temperature changes.

Why should temperature compensation be used for the pressure sensor?

For the diffused silicon pressure sensor, the change of the diffused silicon resistance caused by the temperature change of the measurement 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 experiment. The introduction of temperature error directly affects the accuracy of the measurement result, which is specifically expressed as: the output voltage of the static operating point of the pressure sensor due to the change in the temperature of the measured medium. Therefore, temperature compensation is required.

How should the "temperature drift" phenomenon be controlled?

For the temperature drift of the pressure sensor, it is necessary to select an appropriate compensation method to realize the control of the temperature drift based on specific reasons. Commonly used methods are mainly divided into two methods: hardware compensation method and software compensation method. Microphone sensor uses hardware compensation method. Among the four resistors that make up the Wheatstone bridge, connect the corresponding bridge arms in series and parallel. The resistance value is used to balance the zero drift caused by the mismatch of the initial values ​​of the four diffused silicon resistors, and its temperature drift with temperature changes.

What should I pay attention to when using the pressure sensor?

In addition, when using a pressure sensor, in order to extend the service life of the sensor and save more costs, you also need to pay attention to the following points:

(1) Pay attention to the adaptability of the pressure medium: the corrosiveness, viscosity, and conductivity of the measured medium, pay attention to some special gases (hydrogen, oxygen, etc.);

(2) Pay attention to the power supply size and power consumption;

(3) Pay attention to whether the current is constant current or constant voltage;

(4) Attention should be paid to the selection of the external dimensions, pressure and electrical interface of the sensor during installation;

(5) Pay attention to the ambient temperature and the temperature of the medium: the temperature of the measured medium, different temperatures should choose the appropriate sealing ring for the temperature, there are now a total of low temperature and ultra-low temperature resistant sealing rings to choose from, and the surrounding environment needs to be considered temperature.