| Popis: |
A sensor (1) has a light conductor (2) having a grating (FBG), a cavity (5), and a transparent cavity end wall (4), a light emitter for directing light through the conductor, and a light detector for detecting reflected light, and a processor. The processor is adapted to analyse light reflected due to the grating (FBG, 6) to determine an indication of temperature, light reflected from the end (7) of the cavity (5) to determine an indication of pressure, and also light reflected from the outer surface (8) of the cavity wall (4) to determine an indication of refractive index of a medium outside said cavity wall. The processor may use one output to compensate another, for example pressure and temperature may be used to compensate for variation in refractive index. |
