FIBER OPTIC TEMPERATURE SENSOR Russian patent published in 2023 - IPC G01K11/32 

FIELD: measuring technology.

SUBSTANCE: invention relates to measuring technology and can be used in fiber-optic sensors designed to measure the temperature of large-volume cement, or under the influence of external destabilizing factors on products of rocket-space and aviation technology. A fiber-optic temperature sensor is claimed, containing a source and receivers of radiation, input and output optical fibers fixed in a sleeve opposite the reflective surface of the shank inside the housing. Moreover, a cylindrical tube made of a material with a high coefficient of thermal expansion is additionally introduced into the device, coaxially located inside the body, and the inner diameter of the cylindrical tube is at most equal to the outer diameter of the narrow part of the shank and the outer diameter of the narrow part of the sleeve. The coefficients of linear expansion of the body materials α_B, shank α_S, bushing α_BS and cylinder α_C are determined by the relation X₀=(0,3…0,7)d_C, where d_C is the diameter of the optical fiber core, the lengths of the body l_B and the cylinder l_C are interconnected by the expression l_B=(0,95…1)l_Cα_C/α_B.

EFFECT: reducing internal stresses and, accordingly, increasing the mechanical reliability of the device in large temperature ranges (for example, in the range of -50°C…+100°C); exclusion of sensor housing deformations caused by deformations of a hard environment (for example, concrete) that affect the accuracy of temperature measurement; high accuracy of temperature measurement due to the possible implementation of the compensation conversion of optical signals directly in the zone of measurement information perception; ensuring the tightness of the structure.

10 cl, 3 dwg