Patent ID: 7977417

Claim:
A method, comprising: disposing a cured product of a silicon rubber composition between a structural material that is to be measured with an acrylic optical fiber sensor comprising an acrylic optical fiber, and the acrylic optical fiber sensor, wherein the silicon rubber composition comprises: (A) 100 parts by mass of an organopolysiloxane represented by an average composition formula (1) shown below: R 1 n SiO (4-n)/2 (1) wherein, R 1 represents identical or different, unsubstituted or substituted monovalent hydrocarbon groups, and n represents a positive number within a range from 1.95 to 2.04, (B) 0 to 50 parts by mass of a vinyl group-containing silicon compound, (C) 5 to 100 parts by mass of a reinforcing silica, and (D) an effective quantity of a curing agent, wherein a vinyl group content relative to a combination of components (A) through (D) is at least 1.0×10 −4 mol/g, and monitoring the structural material for distortion with the acrylic optical fiber sensor.