Port Geometry and Gasket Seating on a Pressure Part
Controlled gland squeeze between 15% and 25% prevents mechanical die stress while isolating the pressure port against long-term fluid leakage.
Third Order Polynomial Compensation
Correction Algorithm
A mathematical linearization algorithm calculates cubic curve fit correction coefficients to eliminate non-linear sensor response errors. Smart pressure and temperature transmitters apply third order polynomial compensation to digital raw sensor counts during signal processing. The algorithm corrects non-linear transducer outputs, matching transmitter response to linear engineering units across wide temperature ranges.
The compensation model stops providing valid correction outside the calibrated temperature and pressure boundaries established during characterization.
Mathematical Modeling
Multi-point calibration matrix data populates four polynomial coefficients governing constant, linear, quadratic, and cubic terms. Microcontrollers evaluate the third-degree equation in real time to produce corrected output values.
Precision Improvement
Sensor non-linearity varies across operational temperature ranges, requiring multi-variable matrix math to maintain baseline accuracy. With third order polynomial compensation, residual non-linearity drops below zero point zero one percent of full scale span. The higher-order terms correct inflection points in silicon diaphragm response that simple linear adjustments miss.
Automated test benches generate individual coefficient sets for each transmitter during factory thermal cycling.
Implementation Limit
Processing latency and microcontroller floating-point math capability limit the maximum polynomial order implemented in low-power loop-powered transmitters. Verification against traceable standards ensures polynomial fit residuals remain within target measurement uncertainty budgets.