Table 3.

Comparison between PZT and fiber-optic ultrasonic sensor.

PZT	Fiber-Optic Sensor
Narrow detection bandwidth	Broadband response
Large size (diameter or length in millimeter range)	Small size, light weight, flexibility
Sensitive to electromagnetic disturbances	Immunity to electromagnetic interference
Inadequate resistance to high temperature (Curie temperature, Tc < 60 °C)	High-temperature resistance (operating temperature > 600 °C)
Poor stability of signal transmission (~10 m)	Stabilized transmission in fiber (>20 km)
Poor multiplexing	Good multiplexing, multichannel detection
No direction recognition	Vectorial sensing