Method for fibre-optic temperature measurement, sensor and measurement system employing this method

摘要

The invention relates to a method for fibre-optic temperature measurement, a sensor and a measurement system employing this method. The method according to the invention consists in coupling the mode between the core and the cladding of an optical fibre such that the curve of the luminous power transmitted by this fibre as a function of the temperature P = f(t) has at least one minimum (Ps) for a threshold temperature (ts). This method employs a fibre having a W-shaped profile, which has a locally abraided part filled with a coupling material whose refractive index varies more rapidly with temperature than that of the other constituents of the fibre. The invention applies to any temperature measurement devices, with the possibility of an alarm, in particular in cases where access is difficult or dangerous. IMAGE