Acoustic Emission Measurement by Fiber Bragg Grating Glued to Cylindrical Sensor Holder

Figure 3

Evaluation for directionality of C-FBG sensor. The emitted elastic wave by pencil lead break at each position of circle mark is detected by a C-FBG sensor that was set at the position of the square. The directionality of the sensor is removed if the features of the detected waveforms at each position are similar.