When selecting a pressure sensor, the accuracy of the pressure sensor should be considered. There are many factors that cause sensor errors, and 4 types of errors that pressure sensors cannot avoid are described below:
1. Sensitivity error: the size of the error is proportional to the pressure. If the sensitivity of the device is higher than typical, the sensitivity error will be a function of increasing pressure. If the sensitivity is lower than the typical value, then the sensitivity error will be a decreasing function of pressure. The reason for this error is a change in the diffusion process.
2. Offset error: Since the pressure sensor remains constant in the pressure range of vertical migration, the change of laser adjustment and transformation will produce offset error.
3. Hysteresis error: In most cases, the hysteresis error of the pressure sensor is negligible because the silicon wafer has very high mechanical stiffness. In general, only hysteresis errors in the case of pressure changes need to be considered.
4. Linearity error: This is a small influencing factor for the initial error of the pressure sensor, the error is the cause of physical nonlinear silicon, but the sensor amplifier should also include a nonlinear amplifier. The linearity error curve can be either a concave curve or a convex curve load cell.