The inevitable error of pressure sensors

What are the errors that the pressure sensor can't avoid? We need to consider many factors when selecting the pressure sensor, but some factors are also inevitable. That is the error of the pressure sensor. Let's take a look.

First offset error: Since the vertical offset of the pressure sensor remains constant throughout the entire pressure range, variations in the spread of the diffuser and laser trimming will produce offset errors.

Followed by 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.

The third is the linearity error: This is a factor that has little 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, the nonlinearity of the amplifier should also be included. The linear error curve can be a concave curve or a convex curve load cell.

The last is the lag error: In most cases, the lag error of the pressure sensor is completely negligible, because the silicon has a very high mechanical stiffness. It is generally only necessary to consider the hysteresis error in the case where the pressure changes greatly.

These four errors of the pressure sensor are unavoidable. We can only choose high-precision production equipment, use high technology to reduce these errors, and can also carry out a little error calibration at the factory, and try our best to reduce the error. Meet the needs of customers.