Interference Effect
Unwanted sensor response to temperature variations while measuring a different physical parameter represents a significant challenge in high-precision metrology. In strain gauges and pressure transducers, thermal cross sensitivity occurs when the sensor’s output changes in response to thermal expansion or resistance shifts within the sensing element. This effect can be mistaken for a change in the primary measurand if it is not properly corrected, leading to measurement errors that can compromise the integrity of the data.
Characterization Process
Laboratory tests measure the sensor output across a range of temperatures while holding the primary measurand constant. Calibration engineers compile this data to create a thermal response profile for the sensor. This profile allows the software to calculate the correction factors needed for accurate operation in varying environments.
Compensation Strategy
Integrated temperature sensors measure the local environment directly at the sensing element to allow for real-time digital correction. The micro-controller uses the temperature data to adjust the primary output based on the calculated thermal response profile. This digital correction reduces the temperature-induced error to a fraction of its uncompensated value.
Calibration Boundary
The limits of the temperature compensation algorithm are defined by the temperature range used during calibration. If the sensor is operated outside this specified range, the correction factors may no longer be accurate. The manufacturer lists these boundaries on the calibration certificate.
