Signal Drift
Basal signal deviations occur when the output of a sensor at zero pressure changes due to variations in the ambient temperature. Minimizing thermal zero shift is a primary goal during the design and calibration of precision instruments. This shift is a temporary effect and the output typically returns to its original value once the temperature is restored to the reference level.
Coefficient Variation
Mismatches in the thermal expansion of the housing, the oil fill and the silicon die create internal stresses. These stresses press against the sensing element and appear to the electronics as a real pressure signal. The magnitude of this error is usually expressed in percent of full scale per degree.
Compensation Logic
Active electronics or mathematical models are used to subtract the predicted shift from the actual output. A temperature sensor located inside the housing provides the data needed for this correction. This process ensures that the reading remains accurate even as the sensor heats up during use.
Range Constraint
Effectiveness of the compensation is limited to a specific window, such as minus forty to eighty five degrees Celsius. Beyond these points, the non-linear behavior of the materials makes it difficult to maintain the required accuracy.
