38
(5) Continues like this until detection depth is enough, finishing curve Making.
Refer to Figure 6-11.
Note:
①
there are four curves in the screen (refer to Figure 6-11). The
default displaying order from bottom to top are: access line (-9dB),
ration line (-3dB), generatrix line (0dB), void line (+5dB). The offset
of access line, ration line and void line can be adjust flexibly
according to different flaw detect standards.
②
for convenience, it is permitted to make DAC by staggering the
points. For example, firstly use 20mm, 40mm and 60mm depth
points to make the DAC, then 30mm, 50mm and 70mm depth
points. When all the points are finished, the instrument will
reorganize them automatically and make it a complete set of DAC.
6.2.2 DAC Application
Change DAC mode into dac, then enter DAC application mode.
As DAC is made on test block with highly polished surface, surface compensation
must be made according to surface coupling state before flaw detect, input related
compensate dB value in "COMPENSATE" submenu.
In DAC application mode, instrument can automatically calculate flaw equivalent
and display on upper side of screen as "DAC+**dB".
6.2.3 DAC Amendment
Curve amend: if there is inflexion point on DAC due to hole jamming or unsatisfied
coupling, use amend function to make partial adjustment. Change DAC mode into
amend, choose the point to be modified, adjust the height of it.
6.2.4 Curve deletion
If you are unsatisfied with the completed DAC curve and you want to delete the all
points or some point, you need to select the points you want to delete in the
“SAMP POINT” submenu first. After that, press the [
] key associated with
“DELETE” submenu, then it will be deleted by pressing the associated [
] once
again or [+] key once. If you press [+] key for some time, it will delete the all points
on the DAC curve.
