Dakota Ultrasonics UMX-2 User Manual

Page 25

Dakota Ultrasonics

Dual Element Transducer in Echo to Echo mode

Pulse Echo Coating Mode – Coating On (PECT)

A custom hybrid combination mode using properties from the basic modes along with
a group of special techniques and theoretical wave phenomena’s to measure coating
and material thicknesses at the same time, while still retaining the ability to locate
flaws and pits in materials. Therefore, the best description for this hybrid mode is
Pulse-Echo Coating mode.

Single Element Triple Echo Mode – Time Corrected Gain (TCG)

The TCG mode measures between 3 reflections. Similar to E-E mode, this technique
is commonly used to eliminate errors from surface coatings and also to make
measurements in multiple layered materials. The primary benefit of this mode, is that
a comparison is made, between the 2

and 3

echoes, to verify that a peak jump

has not occurred, providing an additional level of confidence to the measurement.
Generally the disadvantage is that 3 reflections are needed which requires the use of
gates with controllable thresholds to adjust for sensitivity over a given measurement
range. However, the time corrected gain feature built into this mode, automatically
adjusts the gain setting for each individual echo reflection. Therefore all three return
echoes are equal in amplitude or overall signal strength.

Single Element Transducer in Triple Echo (TCG) mode