MICRO-EPSILON C-Box/2A Operating Instructions Manual page 34

Operation
Fig. 15 Recursive average, N = 8
Median:
The median is formed from a pre-selected filter width N (N = 3,5,7,9) for measurement values by re-arranging
the incoming measurement values after each measurement is completed. Then the average value is issued
as a median.
Die maximalen Mittelungszahlen der C-Box/2A sind:
- Median: 9
- Gleitend: 512
- Rekursiv: 32768
This means that individual interference pulses can be suppressed. However, smoothing of the measurement
curves is not very strong.
Example: Median value from five measured values
... 0 1 2 4 5 1 3
... 1 2 4 5 1 3 5
C-Box/2A
Signal without averaging
Signal with averaging
Sorted measurement values: 1 2 3 4 5
Sorted measurement values: 1 3 4 5 5
Application tips
- Permits a high degree of smoothing of the measurement
values. However, it requires extremely long transient recov-
ery times for measured value jumps (low-pass behavior)
- Permits a high degree of smoothing for noise without
strong spikes
- For static measurements, to smooth signal noise
- For dynamic measurements on rough surfaces, to elimi-
nate the roughness, e. g. roughness of paper
- For the elimination of structures, e. g. parts with uniform
grooves, knurled rotary parts or roughly milled parts
- Unsuitable for highly dynamic measurements
Median = 3
Median
(n)
= 4
(n+1)
Page 34