How does an active or passive temperature compensation of pressure transmitters actually work? High-quality pressure transmitters, especially those found in precision critical applications, are almost always provided with an individual temperature compensation. But what is actually the difference between a dynamic and a passive temperature compensation of the sensors?
Passive temperature compensation: Parts of the characteristic accuracy curve of the pressure sensor are measured at different temperatures during the manufacturing process. Then, digital pressure gauge determined temperature errors are compensated by passive elements (resistors) within the electronics of the sensor or by corrections of specifically designed resistance structures directly on the sensor element itself (e.g. by laser-trimming). The (passive) resistor elements used have an almost linear temperature behavior, it is, however, only possible to compensate 1st order errors. Temperature errors of higher order, i.e. strong bending of the characteristic curve under temperature, can’t be compensated.
pressure gauge 10 bar : Here too, the characteristic curve of the pressure transmitters is measured at different temperatures through the manufacturing process. However, the pressure transmitter has an additional integrated temperature sensor which constantly measures the temperature of the sensor and transfers it to the pressure transmitter?s signal processing. In practice, two ways of active temperature compensation are normal: the initial method compensates through a limited amount of samples, , i.e. discrete correction values, between which interpolation occurs.
The second method uses the electronics of the transmitter and a higher-order equation caused by the regression of the acquired measurement values so as to compensate then your expected error. During operation, this signal processing makes it possible to automatically, i.e. ?actively?, compensate pressure gauge ?s temperature error utilizing the calculated correction factors inside a specified temperature range (e.g. 10-60�C). The most commonly used method to minimize temperature errors of pressure sensors is a passive temperature compensation. This can be the traditional method which is widely used.
However, active temperature compensation is the top quality of possible compensation methods. WIKA has constantly improved and refined this technology recently. The pressure transmitters of WIKA using active temperature compensation therefore feature a temperature error that is almost zero in their specified temperature range.