40
6.3.3 Notes
Before Making AVG , you should pay attention to whether probe frequency and
crystal size is suitable, whether the probe parameter settings agree with the actual
and reference curve range is "0.5~23.5mm
,∞
" or not.
6.3.4 AVG Application
In theory, the AVG curve is effective only beyond the triple near field area. Probes
produced by different manufactures have quite different sound field characteristics
within tripe near field area, so you should make AVG by sampling multiple points
or verifying the test block first; otherwise it may occur unnecessary error easily.
The attenuation coefficient between test block and work piece is not considered
when using the AVG.
Compensate should be made when coupling condition changes (different surface
condition of test block and work piece).
6.4 Envelope Function
6.4.1 Summarize
Envelope means profile of echo peak track when probe moves on workpiece, it is
given different color to distinguish from echo itself. According to envelope shape,
users can easily find the highest echo and also make qualitative analysis of flaw
properties. This function can be used along with “Peak Holding” function.
6.4.2 Operation Steps
Enter main menu "MEAS MODE", adjust Envelope submenu item into “on” state.
6.5 Curve Surface Amend
6.5.1 Summarize
When using angle probe to detect cylindrical surface in circumferential direction, it
is difficult to precisely locate the flaw because curve flaw location is indicated by
work piece arc length and depth. For convenience, the instrument will make
automatically calculation and amendment according to curvature of work piece.
