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Control Menu, Set Sensor Parameter
optoNCDT 2300
Median
The median is generated from a pre-selected number of measurement values.
Mode:
To do so, the incoming measurement values (3, 5, 7 or 9 measurement values) are resorted again after every measurement. The aver-
age value is then given as the median. In generating the median in the sensor, 3, 5, 7 or 9 measurement values are taken into account,
that is, there is never a median of 1.
Characteristics:
This averaging mode suppresses individual interference pulses. The measurement value curve is not smoothed to a great extent.
Example: Average from five measurement values
... 1 2 4 5 1 3 5
... 0 1 2 4 5 1 3
Sorted measurement values: 1 3 4 5 5
Sorted measurement values: 1 2 3 4 5
Median
= 3
(n)
Median
= 4
(n+1)
7.4.4.2 Spike Correction
This special form of filtering is used to remove very high spikes from a relatively constant course of measurement values, though while
retaining any smaller spikes. A median would remove all the spikes.
The assessment of whether a measurement is a spike (outlier) is based on the mean of a particular number of previous valid readings.
The permissible deviation from the next value is calculated using the tolerance range. If the new measured value deviates too much, it
will be corrected to the previous value. A maximum number of consecutive measured values to be corrected must also be stated.
Attention: In the event of several consecutive spikes (outliers), the previous corrected value is used in the correction of the following
measured value. Use this function only in appropriate applications. Improper use can lead to a distortion of the measured value se-
quence! Check the possible impact of a changed measured value sequence on the measuring environment and subsequent control-
lers/systems.
This function acts the same way on all output distances; the differences (thicknesses) are calculated on the basis of the corrected
distances.
- x Evaluation length. Number of previous measured values to be assessed (max. 10).
- y Max. tolerance range (mm); the spike (outlier) correction comes into play when the value is not met or is exceeded
- z Number of corrected value (max. 100)
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