© ElektroPhysik
QuintSonic 7
77 von 184
8.5.5
Expectancy domains
Expectancy domains are the opposite of blocked domains. All echoes located within the limits of
expectancy domains will be taken into account for evaluation. Any echo beyond these limits will be
suppressed. Particularity: expectancy domains are not related to fixed time values but to the
individual positions of echoes. They are to be considered as coating thickness ranges. That’s why
this method also very well adapts to layers systems with the thickness of the individual layers
varying strongly. This situation will be described in detail in the following paragraph:
For using the expectancy domain method, the nature of the layer system must be known very well
so that projections can be made as far as the thickness of the individual layers is concerned. Such
information can be obtained from the results of a cross section, for instance. For each expectancy
domain, the user must specify an upper and a lower limit to define the tolerance range within the
limits of which the respective layer thickness values should be situated. For evaluation, these limits
are always related to the position of the preceding valid echo. Thus it can be ensured that only the
current layer will be considered, irrespective of the thickness of the preceding layers and their
respective echoes positions.
Any echo located between the expectancy domains will be classified as being unwanted and
suppressed accordingly. Only echoes located in the expectancy domains will remain. If several
echoes are detected in an expectancy domain, the largest one will be marked as being valid, all
others will be invalid. Any echoes located behind the last expectancy domain are considered as not
being part of any of the expectancy domains and are also invalid.
Each time at least one echo has been detected in an expectancy domain, the system switches to
the next subsequent expectancy domain. That’s why a minimum of one valid echo will be assigned
to each of the expectancy domains. The width of tolerance range depends on the variance in layer
thickness to be expected. The smaller the set tolerance range, the more effective the suppression
of unwanted echoes.
The upper and lower limits (layer thickness values) result from the nominal value and its respective
tolerance. An expectancy domain is completely defined by its upper and lower limits (layer
thickness values). These limits result form a nominal value and the respective tolerances. An
expectancy domain can be either enabled or disabled. Disabled domains will be jumped and