Multiplexed Fibre Bragg Grating Monitoring System for Dynamic and Static Strain Measurements: Sensor System Design and Evaluation : Sustainable Bridges Background document 5.4

• The principle of operation of fibre Bragg grating sensors is based on the Bragg grating sensor element. This is typically a small region of photo sensitive optical fibre (1cm length, 125μm dia. that has been subject to a spatially modulated Ultra Violet (UV) laser beam that produces disruption of the glass that results in changes in periodic modulation of the refractive index down the length of the sensor element with a period pitch of about 1.0 μm. The grating sensor element thus created essentially acts as a wavelength filter for incoming light in which a narrow spectral band is reflected while the remaining light is transmitted and maybe used to interrogate gratings at different centre wavelengths further along down the fibre. This results in a multiplexed sensor system.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Infrastrukturteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Infrastructure Engineering (hsv//eng)

Nyckelord

Fibre Bragg Grating Sensors

Bridges

Byggkonstruktion

Structural Engineering

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