This part of IEC 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.<\/p>\n
This standard specifies the most important features and characteristics of a fibre optic sensor for strain measurements based on use of an FBG as the sensitive element, and defines the procedures for their determination. Furthermore, it specifies basic performance parameters and characteristics of the corresponding measuring instrument to read out the optical signal from the FBG. This standard refers to the measurement of static and dynamic strain values in a range of frequencies.<\/p>\n
A blank detail specification is provided in Annex B.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 6<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 1 Scope 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | Figures Figure 1 \u2013\u00a0Characteristics of the Bragg grating reflectance spectrum <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4 Symbols <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 5 Structure and characteristics 5.1 Fibre Bragg grating (FBG) <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | Figure 2 \u2013\u00a0Operation principle of a fibre Bragg grating in an optical waveguide <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | Figure\u00a03 \u2013\u00a0Reflection spectrum of a fibre Bragg grating array <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 5.2 FBG strain sensor configuration 5.3 Measuring point and installation Figure 4 \u2013 Gauge length between two attachment points <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 5.4 Gauge length 5.5 Strain and reference strain 5.6 Reference wavelength <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 5.7 Stability behaviour 5.7.1 Drift and creep 5.7.2 Shape stability of the Bragg grating peak 5.7.3 Hysteresis 5.8 Test specimen <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 5.9 Indication of the measured values 5.10 Zero point related measurement 5.11 Non-zero point related measurement 5.12 Production set 5.13 FBG strain sensor standard type 5.14 FBG strain sensor series 6 Features and characteristics to be reported 6.1 Construction details and geometrical dimensions <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 6.2 Configuration of the FBG strain sensor 6.3 Temperature and humidity range 6.4 Connecting requirement 7 Features and characteristics to be measured 7.1 Sampling and statistical evaluation 7.1.1 Sampling 7.1.2 Random sampling 7.1.3 Type testing 7.1.4 Series testing <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 7.1.5 Individual sample testing 7.1.6 Reporting the measuring result 7.1.7 Sample conditioning 7.1.8 Ambient test conditions 7.1.9 Required type of test for individual characteristics Tables Table 1 \u2013 Required type of test for individual characteristics <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 7.2 Bragg wavelength \u03bbB 7.2.1 General 7.2.2 Measuring procedure Figure 5 \u2013\u00a0Reflection spectrum of a FBG [calculated (left) and measured spectrum (right)] <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 7.2.3 Evaluation 7.2.4 Reporting 7.3 FBG spectral width 7.3.1 Measuring procedure 7.3.2 Evaluation 7.3.3 Reporting 7.4 FBG reflectivity 7.4.1 Measuring procedure <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 7.4.2 Evaluation 7.4.3 Reporting 7.5 FBG Strain sensitivity 7.5.1 General Figure 6 \u2013 Determination of RFBG from the FBG reflection spectrum (left, Equation (9)) and transmission spectrum (right, Equation (10)) <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 7.5.2 Tensile test set-up 7.5.3 Measuring procedure tensile test Figure\u00a07 \u2013 Example set-up of a tensile test facility <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 7.5.4 Evaluation 7.5.5 Reporting 7.6 Gauge factor k 7.6.1 General <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 7.6.2 Bending test set-up Figure 8 \u2013 Test layout (left) for the 4-point bending test with scheme of lateral force and bending moment curves (right) <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Figure 9 \u2013 Determination of the strain via displacement measurement <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 7.6.3 Measurement procedure Figure 10 \u2013 Whole-surface applied sensor on a bended flexural beam <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 7.6.4 Evaluation 7.6.5 Reporting 7.7 Maximum strain range at room temperature 7.7.1 General 7.7.2 Test set-up <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 7.7.3 Measuring procedure 7.7.4 Evaluation 7.7.5 Reporting <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | 7.8 Fatigue behaviour 7.8.1 Test set-up 7.8.2 Measuring procedure 7.8.3 Evaluation Figure 11 \u2013 Test specimen with applied FBG strain sensor <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 7.8.4 Reporting 7.9 Minimum operating radius of curvature 7.9.1 Measuring procedure 7.9.2 Evaluation 7.9.3 Reporting 7.10 Temperature and humidity ranges 7.10.1 General <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 7.10.2 Measuring procedure 7.10.3 Evaluation 7.10.4 Reporting 7.11 Other environmental influences 7.12 Temperature-induced strain response 7.12.1 General <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | 7.12.2 Test set-up <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 7.12.3 Measuring procedure 7.12.4 Evaluation 7.12.5 Reporting 7.13 Proof test and lifetime considerations 7.13.1 General <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 7.13.2 Measuring procedure 7.13.3 Evaluation <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | 7.13.4 Reporting 8 Recommendations for use of FBG measuring instruments <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | Annex A (informative) Further properties of FBG strain sensors A.1 General A.2 Extended explanation of FBG side-lobes for different conditions of use <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | Figure A.1 \u2013 Side-lobes in the case of a single FBG strain sensor Figure A.2 \u2013 Fundamental peaks and detected side-lobe peaks in the case of serially multiplexed FBGs <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | Figure A.3 \u2013 Spectral peaks in the case of serially multiplexed FBGs Figure A.4 \u2013 Parameters to identify fundamental peaks and side-lobes <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | Figure A.5 \u2013 Identification of fundamental peaks and side-lobes <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | Annex B (informative) Blank detail specification B.1 General B.2 Mechanical setup of the FBG strain sensor B.3 Operational characteristics of the FBG strain sensor <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | B.4 Limiting parameters of the FBG strain sensor B.5 Temperature data of the FBG strain sensor B.6 Further information of the FBG strain sensor given upon request B.7 Key performance data of the FBG measuring instrument <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | Annex C (informative) Polarization effects <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | Annex D (informative) Applied FBG strain sensors D.1 General D.2 Recommended bonding process <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Fibre optic sensors – Strain measurement. Strain sensors based on fibre Bragg gratings<\/b><\/p>\n |