Temperature measurement and compensation in a fiber-optic sensor

摘要

A fiber-optic sensor for measuring a parameter of a test fluid, including a chemical sensor, incorporating a dye composition which displays changes in its optical properties correlated to changes in the parameter to be measured. The sensor is coupled to an apparatus including a light source, and means for measuring light received from said sensor at three different peak wavelengths. The first wavelength is chosen such that the optical characteristics of the dye with respect to that wavelength do not change significantly with changes in the parameter to be measured. The second and third wavelengths are chosen such that optical characteristics of the dye with respect to these wavelengths do change along with changes in the parameter to be measured, and also change as a function of temperature. The light received from the sensor at first, second and third wavelengths is compared to determine the temperature of the test fluid and to provide a temperature correction for the parameter to be measured.