BS EN 61757-1-1:2017 pdf free.Fibre optic sensors.Strain measurement一Strain sensors based on filbre Bragg gratings. BS EN 61757-1-1 This part of lEC 61757 defines detail specifications for fibre optic sensors using one or more fibre Bragg gratings (FBG) as the sensitive element for strain measurements. Generic specifications for fibre optic sensors are defined in IEC 61757-1:2012.This standard specifies the most important...