382 WM-OM-E Rev I
The baselines are found by locating a point at which the waveform ‘rests’ between the peak and
trough and peak. These resting points are identified by statistically measuring the area of least
change in voltage value between the peak and trough or trough and peak, with internal tolerance
levels set to ensure against false baseline identification.
Another condition for identification is that the resting points must fall within a band, centered around
the midpoint of the peak and trough extremes, whose height is 2/3 of the peak-to-trough height.
If one of the baselines cannot be identified, the local baseline is set to the found value. If neither
baseline can be identified, then the local baseline is set halfway between the extremes of the local
feature’s peak and trough.
If baselines can be identified on both falling and rising slopes, the local-feature baseline is an
average of the two baselines and 1 bsep is the distance between them.
If the local feature is the last to be identified before arriving at the end of the region being analyzed,
it will not be possible to identify the trough-to-peak baseline of the following local feature. But when
the peak-to-trough baseline is identified, then these two baselines are assumed to be separated by
the same distance as the baselines for the previous local feature. And if this baseline cannot be
identified, then the local baseline becomes the midpoint of the local peak and trough.
The separation between the baselines (local baseline separation) can also be of interest in
determining the validity of certain measurements.
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