Abstract: Testing method for determining the distribution of a physical property along a wind turbine blade comprising the following steps: a) installing inside the blade a first optical fiber cable (13) along the leading and trailing edges and a second and third centered optical fiber cables (14, 15) at both sides of the blade (9), leaving in them a free end; b) applying one load to the blade (9) in a test bench (10) placed at the blade factory; c) obtaining the strain distribution produced by said load along the blade (9) using a suitable external equipment connected to said free end for measuring the strain using Rayleigh scattered light; d) determining the distribution of said physical property from said strain distribution; e) comparing the distribution of said physical property with its design distribution. The invention also comprises a method of installation of said cables.

Abstract: A current transformer (5) having a plurality of primary and secondary windings, comprising a top Strain measuring system of wind turbine blades (11) during the performance of static tests that comprises an equipment for measuring the strain at multiple locations in mono-mode optical fibers (5, 7, 9) using Rayleigh scattered light, that includes an OBR interrogator (23), an interface device (25) and an Acquisition System (27), said mono-mode optical fibers (5, 7, 9) being attached to the blade (11) subjected to said tests for obtaining high spatial resolution measurements of the blade strain during said tests. Said optical fibers (5, 7, 9) may be placed whether in a longitudinal direction or in a non-longitudinal direction or in a non-linear shape in given blade sections and may be bonded whether to the outer skin (31) of the blade (11), or into grooves (51, 53) in the outer skin (31) of the blade (11) or embedded between two structural laminates (33, 35) of the blade (11).

Abstract: Testing method for determining the distribution of a physical property along a wind turbine blade comprising the following steps: a) installing inside the blade a first optical fibre cable (13) along the leading and trailing edges and a second and third centered optical fibre cables (14, 15) at both sides of the blade (9), leaving in them a free end; b) applying one load to the blade (9) in a test bench (10) placed at the blade factory; c) obtaining the strain distribution produced by said load along the blade (9) using a suitable external equipment connected to said free end for measuring the strain using Rayleigh scattered light; d) determining the distribution of said physical property from said strain distribution; e) comparing the distribution of said physical property with its design distribution. The invention also comprises a method of installation of said cables.

Abstract: A current transformer (5) having a plurality of primary and secondary windings, comprising a top Strain measuring system of wind turbine blades (11) during the performance of static tests that comprises an equipment for measuring the strain at multiple locations in mono-mode optical fibres (5, 7, 9) using Rayleigh scattered light, that includes an OBR interrogator (23), an interface device (25) and an Acquisition System (27), said mono-mode optical fibres (5, 7, 9) being attached to the blade (11) subjected to said tests for obtaining high spatial resolution measurements of the blade strain during said tests. Said optical fibres (5, 7, 9) may be placed whether in a longitudinal direction or in a non-longitudinal direction or in a non-linear shape in given blade sections and may be bonded whether to the outer skin (31) of the blade (11), or into grooves (51, 53) in the outer skin (31) of the blade (11) or embedded between two structural laminates (33, 35) of the blade (11).