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IM WT1801-01EN
Data Update Interval (UPDATE RATE)
The data update interval is the interval at which the data that is used in measurement functions is sampled.
You can select the data update interval from the options below.
50 ms, 100 ms, 200 ms, 500 ms, 1 s, 2 s, 5 s, 10 s, and 20 s
At each data update interval, the numeric data is updated, stored, transmitted through a communication
interface, and converted and output as analog signals.
To capture relatively fast load fluctuations in the power system, select a fast data update rate. To capture low
frequency signals, select a slow data update rate.
Fast
The WT1800 switches to the next fastest data update interval (out of the intervals listed above).
Slow
The WT1800 switches to the next slowest data update interval (out of the intervals listed above).
Current Rate
Displays the current data update interval. You can press a soft key to select a data update interval from the
options listed above.
• The display update intervals of numeric data and waveform data may be longer than the data update
interval.
• The lowest measurable AC signal frequency varies depending on the data update interval. The measured
value may not be stable if an AC signal of a frequency lower than the low frequency measurement limit (see
section 6.5 in the getting started guide, IM WT1801-03EN) is measured.
Averaging (AVG)
You can take exponential or moving averages of the numeric data. The averaging function is effective when
reading of the numeric display is difficult due to fluctuations. This occurs when the fluctuation of the power supply
or the load is large or when the input signal frequency is low.
Turning Averaging On and Off (Averaging)
Measurement Functions Used in Normal Measurement
You can select whether to average values. When you enable averaging (ON), the AVG key and the AVG indicator
at the top of the screen illuminate.
Measurement Functions Used in Harmonic Measurement (Option)
• If averaging is turned on, and the averaging type is Exp (exponential averaging), averaging is performed on
harmonic measurement functions.
• Even if averaging is turned on, if the averaging type is Lin (moving average), averaging is not performed on
harmonic measurement functions.
2 Fundamental Measurement Conditions