ThermoLux ®


Fiber optic temperature sensor

ThermoLux capteur de température à fibre optique Cementys

A sensor for accurate and reliable temperature measurement using fiber optics

The ThermoLux© temperature sensor is designed to measure temperature locally on one or more points. The measuring range is typically from -30 to 80°C. It can be increased on demand (up to 280°C).

The ThermoLux© sensor consists of a 316L stainless steel tube. In this tube is inserted a silica optical fiber, in which are inscribed one or more Bragg gratings. The Bragg grating is a passive optical microcomponent photo-inscribed inside the fiber.

During its reading (like a barcode) this grating is flooded by a wide spectrum light and reflects only one wavelength, proportional to the grating’s pitch, which will be analyzed by a specific interrogator.

Temperature variations induce variations in the pitch of this grating as well as in the index of the optical fiber, in turn inducing variations in the reflected wavelength. The grating’s reading can be done from several kilometers away.


This sensor is particularly designed for sensitive structures and infrastructures requiring reliable monitoring:

      •  Dams and dykes

      • Nuclear power plants

      • Bridges and viaducts

      • Storage facilities and reservoirs

      • Tunnels and pipelines

      • Plateformes Offshore en béton


Structures concerned