Four errors that pressure sensors can't avoid - News - Global IC Trade Starts Here Free Join

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When choosing a pressure sensor, we should consider his comprehensive precision, and what is the accuracy of the pressure sensor? In fact, there are many factors that cause sensor errors. Below we pay attention to four unavoidable errors, which is the initial error of the sensor.
First offset error: Since the vertical displacement of the pressure sensor remains constant over the entire pressure range, changes in converter diffusion and laser adjustment correction will produce offset errors.
Second is the sensitivity error: the magnitude 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 the pressure. If the sensitivity is lower than the typical value, the sensitivity error will be a decreasing function of the pressure. This error is caused by a change in the diffusion process.
The third is linearity error: this is a factor that has less influence on the initial error of the pressure sensor. The error is caused by the physical nonlinearity of the silicon wafer, but for the sensor with the 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.
Finally, the hysteresis error: in most cases, the hysteresis error of the pressure sensor is completely negligible because the silicon wafer has a high mechanical stiffness. It is generally only necessary to consider the hysteresis error in situations where the pressure varies greatly.
These four errors of the pressure sensor are unavoidable. We can only choose high-precision production equipment, use high-tech to reduce these errors, and perform a little error calibration at the factory to minimize the error. Meet the needs of customers.
There are many problems to be aware of when selecting a pressure sensor. Only when you understand how the pressure sensor works can you choose a pressure sensor. For example, the range of the pressure sensor, the accuracy, the temperature characteristics of the pressure sensor, and the chemical characteristics are all considered. The operation of the pressure sensor is also an important issue to consider.
For example, the sensor is used for the measurement of gas pressure and the measurement of liquid pressure is different. The gas is a compressible fluid, which stores a certain amount of compression energy when it is replenished. When it is decompressed, it is released by kinetic energy, and a shock wave is applied to the elastic film of the sensor. The pressure sensor is required to have a large overload capacity. The liquid is an incompressible fluid. When the pressure sensor device is tightened, there is no compressible space, and the liquid pressure rises beyond the pressure limit of the elastic film, causing the elastic film to rupture. Since this situation occurs frequently, the pressure sensor is also required to have a large overpressure capability.
When the working environment of the pressure sensor is bad, for example, there are large vibrations, impacts, and large electromagnetic interference, which impose stricter requirements on the sensor. Not only the over-pressure capability is strong, but also the mechanical seal is required to be reliable, anti-loose, and the sensor device is correct. The sensor's own leads, leads and external leads should be electromagnetically shielded and the shield grounded well.
In addition, consideration should be given to the compatibility of the pressure sensor with the fluid medium being measured. For example, the elastic membrane structure of the sensor should be separated from the corrosive medium. At this time, a stainless steel bellows sensor is used, and the silicone oil is used as a pressure transmitting medium in the sensor. When the sensor detects the pressure of flammable and explosive media, use a small excitation current to prevent sparks and sparks from breaking when the elastic film breaks, and increase the pressure resistance of the pressure sensor casing.