Olympus EPOCH 650 User Manual page 336

DMTA-10055-01EN, Rev. A, February 2015
Term
Excitation pulse
Filter
First critical angle
Flaw
Frequency
Gain
Gate
Hertz (Hz)
324 Appendix C
Table 32 Glossary (continued)
The pulse of electrical energy sent by the pulser to the
transducer, sometimes known informally as the main
bang. Both spike (broadband) and square wave (tuned)
excitation pulses are commonly used.
Receiver function that passes selected frequency
components of a signal and rejects others, used to improve
signal-to-noise, near surface resolution, and dynamic
range. Filters may be high pass, low pass, narrowband, or
broadband.
In angle beam or immersion testing, the minimum
incident angle in the wedge or water path at which the
refracted longitudinal wave disappears from the test piece.
A discontinuity that may be undesirable but does not
necessarily call for rejection, depending on procedural
requirements.
The number of complete cycles per second undergone or
produced by an oscillating as body expressed the
reciprocal of the period t.
Used in electronics with reference to an increase in signal
power; usually expressed as the ratio of the output power
to the input power in decibels.
A software function that selects and marks a portion of the
displayed range for measurement of distance or
amplitude.
The unit of frequency, defined as the frequency of a
periodic phenomenon of which the period is one second;
equal to one cycle per second.
1 kilohertz (kHz) = 10
1 megahertz (MHz) = 10
Definition
f = 1/t
cycles per second
3
cycles per second.
6