Sensor response calibration for linearization

摘要

A method for determining an unknown input measurand Punk of a sensor having a linear response at small input measurand levels and a non-linear response at large input measurand levels.

主权项

1. A method for linearizing a sensor having a linear response at small input measurand levels and a non-linear response at large input measurand levels, the method comprising:
(a) identifying a reference calibration function Pref(U) for sensors of a given type, where argument U is a sensor output signal and Pref is a measurand value; (b) calibrating the sensor with respect to the reference calibration function Pref(U) by:
(i) determining a first coefficient G to adjust sensor sensitivity to fit the function Pref(U) at low measurand levels;(ii) determining a second coefficient K, which, when it multiplies both a sensor output and a measurand value, stretches a response curve of the sensor to fit the function Pref(U) at high measurand levels; (c) applying a post-calibration correction of the sensor output to an unknown input measurand Punk by:
(iii) applying the unknown input measurand Punk to the sensor;(iv) obtaining an output Um from the sensor; and(iv) calculating the input measurand from Punk=Pref(K·G·Um)/K.