To describe a new optical fibre Bragg grating (FBG) sensor system, based on a novel time division multiplexing technique, which is being commercialised by UK start‐up Insensys. This new technique allows sensor costs to be reduced dramatically and also yields operational benefits.Design/methodology/approach – The system uses time division multiplexing (TDM) rather than wavelength division multiplexing (WDM) to interrogate the sensors. All the FBG sensors are written at the same wavelength and the interrogation unit receives a number of pulses from each grating. These pulses arrive at a time determined by the grating distance from the interrogator and one grating sensor can be distinguished from another by analysing the pulse arrival times. As a result, there is no need for a tuneable laser or filter and a single mask can be used to write all of the gratings, thus reducing both manufacturing and component costs.Findings – This design has led to lower costs and allows up to 100 strain or temperature sensors to be incorporated into a single channel system, rather than around 4, which is the norm for conventional WDM systems. The company is now in production and has orders for systems to monitor the strain in wind turbine blades, to measure temperature profiles in oil wells and to monitor the stress in composite structures.Originality/value – This TDM‐based design allows FBG sensor systems to measure far more points per fibre than is possible with conventional WDM system, combined with lower system costs. Applications are being found in the marine, aerospace, offshore and power generation industries.
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