Protection circuitry and time resolution in high frequency ultrasonic NDE

Ultrasonic testing systems commonly employ voltage limiters to protect the display unit or pre-amp from the large pulses used to excite the transducers. These voltage limiters can seriously distort the shapes of echo signals, and degrade time resolution in signals centered above 30 MHz. The potential to avoid these problems by replacing the limiter with a fast high-voltage switching circuit is measured for two experimental systems.