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GMC-I Gossen-Metrawatt GmbH
47
GB
21.3
Line Fault Recording with Memory Mode
A much greater number of events can be stored to mem-
ory if the memory mode is activated. See chapter 22.
Measurement values resulting from the following measuring
functions are stored to memory:
• Line voltage V AC+DC TRMS (sampling rate: 500 ms).
Measuring voltage is stored together with trigger and
hysteresis settings.
• Drop outs (sampling rate: 20 ms) are stored as a curve
with 10 ms interpolation points for a maximum duration
of 1 s. The last 10 values which occur before triggering,
“drPout”, remain in memory.
• Voltage peaks (pulses) are stored to memory if the
“PULSE” trigger threshold is exceeded.
• Simultaneously occurring events are stored to a special
main memory (max. 250 events).
22
Storing Measurement Values with the METRA HIT 29S
The instrument is equipped with a quartz movement syn-
chronized measurement value memory (128 kB), which
holds an average of 50,000 measurement values. Mini-
mum capacity is 20,000 values (if large signal deviations or
time spans occur between the measurement values). Max-
imum capacity is 100,000 measurement values (minimal
signal deviation, rate
≥
0.5 s, hysteresis = „ALL“). The mea-
surement data are stored as so-called data blocks. Mea-
surement values from the same measuring function are
stored in the same block. Data are acquired relative to real-
time. Thus the instrument may also be used as a real-time
data logger.
Only absolute values and absolute time records can be
stored (no relative or
Δ
values, and no relative time records).
Memory content can only be read out with the help of a
PC, an infrared adapter and METRAwin
®
10/
METRA
Hit
®
analysis software.
Preparations for Memory Mode Operation
Note!
☞
First set
hysteresis
,
sampling rate
and
triggering param-
eters
for memory mode operation, and then activate
the memory mode. These parameters cannot be
changed during operation in the memory mode, or
the transmission mode.
➭
Select the desired measuring function, as well as an
appropriate measuring range. In the automatic measur-
ing range selection mode measuring breaks and/or over-
flow „OL“ may occur when switching between the mea-
suring ranges. We therefore recommend the manual
range selection mode when using the memory function.
➭
Check the charging level of the battery before starting
long-term measurement value recording (see Chapter
26.1, page 74). Connect the AC power pack if neces-
sary.