1. The concept and importance of linearity
Linearity is one of the key performance indicators of High Performance Pressure Transmitter. Simply put, linearity describes how closely a pressure transmitter’s output signal approximates a straight-line relationship with the input pressure. Ideally, when a pressure transmitter is subjected to pressure changes, its output signal (such as current or voltage) should have a perfectly linear relationship with the pressure, that is, it should change uniformly according to a fixed ratio. This property is of vital importance in many industrial applications. For example, in the chemical production process, if the linearity of the pressure transmitter is poor, it may lead to misjudgment of the pressure in the container, which will affect the safety and product quality of the entire production process. In a precise flow measurement system, the linearity of the pressure transmitter is directly related to the accuracy of the flow calculation, because the flow rate is often measured indirectly through the pressure difference.
2. Factors affecting the linearity of High Performance Pressure Transmitter
First, the type and structure of the sensor have a significant impact on linearity. For example, piezoresistive sensors work based on the piezoresistive effect of semiconductor materials. However, the characteristics of semiconductor materials are not completely ideal, and their piezoresistive coefficients will change nonlinearly with changes in pressure. In addition, the structural design of the diaphragm in the sensor is also critical. If the shape and thickness of the diaphragm are uneven, the deformation under pressure cannot completely follow the ideal linear mode, thus affecting the linearity of the transmitter.
Secondly, the accuracy of the manufacturing process is also an important factor. During the manufacturing process, any slight dimensional deviation, material unevenness, or assembly error may cause linearity to degrade. For example, if there is a slight thickness difference in the sensitive element of the sensor during manufacturing, different strains will be produced when pressure is applied, causing the output signal to deviate from the linear relationship.
3. Typical performance of linearity of High Performance Pressure Transmitter
High Performance Pressure Transmitter typically has excellent linearity. Generally speaking, its linearity error can be controlled within ±0.1% - ±0.5%. This means that the output signal deviates very little from the ideal linear relationship over the entire pressure measurement range. For example, for a High Performance Pressure Transmitter with a measurement range of 0 - 10MPa, when the pressure is 5MPa, its output signal has minimal deviation from the signal calculated according to the ideal linear relationship. Such linearity can meet the needs of most high-precision industrial applications, such as precise monitoring of pressure in aircraft hydraulic systems in the aerospace field, and precise measurement of small pressure changes in production equipment in the pharmaceutical industry.
4. Technical measures to improve linearity
To improve linearity, manufacturers employ a variety of advanced technologies. In terms of sensor design, precise structural optimization is carried out, such as using a diaphragm of special shape and material to make its deformation under pressure closer to linear. At the same time, more advanced material processing technology is used to ensure the uniformity of the material. In the signal processing link, microprocessors and specialized linearization algorithms are used. By collecting and analyzing the original signal output by the sensor, and then using a linearization algorithm to correct the nonlinear signal, the linear relationship between the final output signal and pressure is more accurate, further improving the linearity of the High Performance Pressure Transmitter.
