A Fiber Bragg Grating-Based Condition Monitoring and Early Damage Detection System for the Structural Safety of Underground Coal Mines Using the Internet of Things

<div>(a) Strain variations of FBG strain sensors at sections 1 and 2. (b) Strain variations of FBG strain sensors at sections 3 and 4.</div>

Journal of Sensors

fig8

Figure 8

Figure 8: A Fiber Bragg Grating-Based Condition Monitoring and Early Damage Detection System for the Structural Safety of Underground Coal Mines Using the Internet of Things 

Figure 8 | A Fiber Bragg Grating-Based Condition Monitoring and Early Damage Detection System for the Structural Safety of Underground Coal Mines Using the Internet of Things 