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12.1.3.5 Histograms
For histograms, information on the absolute time is not relevant for the results. The information gained is on how long
the signal remained within a particular range (classification).
Frequency_his to
%
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
45
46
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12.1.4 Memory management
12.1.4.1 Aggregation interval
In normal cases, mean values are formed over 10 minute intervals, which results in a very small data volume. 10-
minute-values can even be kept for a week in the device's internal RAM.
In order to obtain more data on how a quantity changes (especially the upper harmonics), it is also possible to
sample at intervals of whole seconds. It thus becomes possible to observe sudden jumps of an upper harmonic.
Signal voltages even require a 3-second interval. However, such a measurement cannot be sustained for a long time
due to the huge amounts of data which accumulate.
Data volume (per voltage channel) in Bytes for different combinations of aggregation interval and
measurement time
Bold and italic entries are required for the EN 50160.
Interval
10 min
13 k
14 k
5 min
10 s
107 k
330 k
3 s
Since the data volume also depends on the amount of disturbance, the actual memory requirements can deviate from
the values indicated above.
The data volume expected is displayed as per the settings in the memory management dialog Memory management
(see System manual).
For an EN50160 measurement over 3 voltage channels (including frequency and symmetry measurement) and an
aggregation interval of 10 min, about 1,2 MByte of data accumulate per week.
A four-phase measurement of U,I + power calculation requires approx. 650 kByte per day.
48
49
50
51
Measurement time
1 h
1 day
1 week
50 k
300 k
90 k
600 k
25 M
16 M
8 M
53 M
Calculation of histograms is performed
subsequently on the PC. It can be carried
out for every channel which was sampled
equidistantly (in contrast to XY-data of the
reduced measurement channels).
52
53
54
55
Hz
A voltage channel includes:
mean value
max., min. value in the aggregation interval
mean value of harmonics
flicker
data reduced curve plot
Power Quality Recorder SICAM Q80 7KG8080, Operating instruction
Computations
E50417-B1074-C419-A2, Release 12.01.2015
E-61
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