DAKOTA ULTRASONICS MiniMax v2.0, Руководство по эксплуатации

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bolt, and resulting in a return echo slightly longer than the overall length of the bolt.
A detection can only occur inside of the boundaries of the gate. Therefore, setting
the start of the gate beyond the first reflection from the end of the bolt will force the
MiniMax to look for the next detection. In this case a mode conversion.
Another potential issue is general transducer or low frequency noise. In this type of
situation, the noise interferes with the
MiniMax
and has enough amplitude to cause
the
MiniMax
to detect on the noise rather than the true return reflection. The
diagram below illustrates both cases:
Gate
The horizontal line at the top of
(D) represents the GATE . The starting point of
GATE has been adjusted just beyond the noise (A) , so that the
MiniMax
ignores the
noise and detects on the true back wall reflection (C) . Alternatively, the diagram can
also be considered as (A) representing the actual reflection from the end of the bolt,
and the gate (B) blocking the detection of (A) to use the mode conversion (C) .
Finally, it’s important to note that the threshold level (sensitivity) is the height of (D) .
The bottom of (D) is at the baseline, and the further away (D) gets from baseline the
less sensitive it becomes. The height/amplitude of a waveform must meet or exceed
the threshold level in order to detect. Therefore, the horizontal distance of
(B) from
the baseline represents the threshold level, which is is indicated by the horizontal
position of the gate.
Adjusting the Gate using the Hot Menus