Four kinds of errors that pressure sensors cannot avoid
When selecting a pressure sensor, consider its overall accuracy, and what are the effects of pressure sensor accuracy? There are many factors that cause sensor errors. The four errors that pressure sensors cannot avoid are as follows:
1, the sensitivity error: the size of the error is proportional to the pressure. If the sensitivity of the device is higher than the typical value, the sensitivity error will be an increasing function of pressure. If the sensitivity is lower than the typical value, the sensitivity error will be a decreasing function of pressure. The reason for this error is the change in the diffusion process.
2. Offset error: Since the vertical offset of the pressure sensor is kept constant throughout the entire pressure range, deviations in the spread of the diffuser and the laser adjustment will produce an offset error.
3. Hysteresis error: In most cases, the hysteresis error of the pressure sensor is completely negligible because of the high mechanical stiffness of the silicon wafer. It is generally only necessary to consider the hysteresis error in the case where the pressure changes greatly.
4. Linearity error: This is a factor that has a small influence on the initial error of the pressure sensor. The reason for this error is the physical nonlinearity of the silicon, but for the sensor with amplifier, it should also include the nonlinearity of the amplifier. The linear error curve can be a concave curve or a convex curve load cell.