A Device For Monitoring Soil Pressure And Temperature

The present invention relates to a device for monitoring soil pressure and temperature, comprising of : an elongated optical fiber embedded with at least two fiber Bragg grating sensors (FBGs), namely the fiber Bragg grating pressure sensor (FBGP) and fiber Bragg grating temperature sensor (FBGT) for simultaneous pressure and temperature sensing; a horizontal actuator is sandwiched between a pair of plates mounted on top of the actuator to withstand applied loads and on the bottom of the actuator acting as a base, wherein, the actuator further comprises of a circular section including an aperture member position parallel at each side of the circular section; characterized in that: said elongated fiber is inserted longitudinally into the circular section of the actuator extending across the other end of the circular section through both the aperture members with the FBGP, affixed within the actuator to optimize strain transfer from the load applied from the actuator to the FBGP; the elongated fiber at the other end of the circular section further comprises of the strain-free FBGT unattached and position separately from the actuator to monitor wavelength shift and temperature change; and a protective casing encasing the actuator and the FBGs to optimize and evenly distribute strain transfer from external soil to the FBGs.