Figure 10-14 Examples Of The Interface Blank In Mode 2 - Olympus 45MG User Manual

set as short as possible to avoid unnecessarily restricting minimum measurable
thicknesses. The initial gain parameter often helps reduce the interface echo
amplitude, and permits the use of a shorter interface blank. Check the interface blank
settings with the transducer both coupled to and uncoupled from the test material.
Gage reading trailing edge of the
interface echo

Figure 10-14 Examples of the interface blank in mode 2

In mode 3, the interface blank selects which pair of back-wall echoes are measured
(see Figure 10-15 on page 182). In most conditions, the interface blank would be set
just short of the first back-wall echo. However, as a practical matter, the first back-wall
echo from thin materials is often distorted or lost in the interface echo. With some
challenging geometries (such as tight radii), later pairs of back-wall echoes may be
cleaner than early ones. In such cases, set the interface blank to a length that ensures
detection of a clean and well-defined pair of back-wall echoes, even if the echoes are
not the first two.
Custom Setups for Single Element Transducers
DMTA-10022-01EN, Rev. C, January 2015
Interface blank set correctly
181