Olympus EPOCH 650 - Peak Hold; Freeze; Gate Tracking and Echo-to-Echo Measurements

DMTA-10055-01EN, Rev. A, February 2015
Chapter 6 118
6.3 Peak Hold
The peak hold function is similar to peak memory as it captures the current screen
when the function is accessed. The difference is that with peak hold, the captured
waveform is frozen on the screen and does not update even if the live waveform
exceeds the frozen waveform’s amplitude.
Peak hold is useful when you want to obtain a waveform from a known sample and
compare it to a waveform from an unknown test piece. Similarities and/or differences
in the waveforms can be noted to help determine the acceptance criteria for the
unknown material.
To activate peak hold
1. Obtain an echo on the screen.
2. Press 2
ND
F, (PEAK HOLD).
This captures the screen and still allows viewing of the live waveform. The
symbol appears on the right side of the A-scan display indicating that the
function is active.
3. Press 2
ND
F, (PEAK HOLD) again to shut off the peak hold function.
6.4 Freeze
The freeze function holds, or freezes, the information on the screen at the moment at
the moment it is activated. Once the freeze function is activated, the pulser/receiver of
the EPOCH 650 ultrasonic flaw detector becomes inactive and does not acquire any
further data. A freeze ( ) symbol appears on the right side of the screen indicating
that the function is active.
There are two ways to activate the freeze function: manual and automatic. Manual
freeze requires you to press the FREEZE key to activate the function. Automatic freeze
(Auto-Freeze) allows you to automatically activate the freeze function based on any
triggered gate alarm.
To activate the freeze function manually
 Press FREEZE.