Hioki LR8400-20, Инструкция по эксплуатации

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3.8 Suppressing Noise (Enable Digital Filtering)
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Electrical noise mixed with input signals can be removed by digital filtering.
Noise suppression is most effective for longer recordings, where it can provide higher
measurement accuracy and less scattering.Unless the timing difference between chan-
nels needs to be minimized, we recommend selecting 50 or 60 Hz to match the local line
frequency.
See: "Cut-off frequency" (p .239)
Make these settings on the [Setting] screen.
See:
"Time Setting by Key Operations" (p .52)
3.8 Suppressing Noise (Enable Digital Filtering)
The Setting screen cannot be displayed while measuring.
Setting Procedure
[Filter]
Setting options:(
∗
: default setting)
60Hz
∗
, 50Hz, OFF
Fc: Cut-Off Frequency
• Select 50 or 60 Hz to match the local line frequency.
• When 50 or 60 Hz is selected, longer recording intervals provide lower cut-off frequencies and
better noise suppression.
• A larger number of channels (input units) raises the cut-off frequency for a specific recording
interval, and weakens noise suppression.
See:
"Cut-off frequency" (p .239)
• When 50 or 60 Hz is selected, the measurement timing difference between channels
increases relative to the recording interval.
Disable filtering (set to Off) to minimize the timing difference between channels (to within 500
μ
s for adjacent channels, and 10 ms for all channels).