YOKOGAWA WT310EH - Page 124

App-18
IM WT310E-01EN
As another example, if an inverter is being measured and the current waveform distortion is smaller
than the voltage waveform distortion, set the synchronization source to the current signal.
Voltage
waveform
Current
waveform
Synchronization source
set to the current signal
Zero Crossing
• Therising(orfalling)zerocrossingisthetimewhenthesynchronizationsourcepassesthrough
level zero (the center of the amplitude) on a rising (or falling) slope. The measurement period on
this instrument is between the first rising (or falling) zero crossing and the last rising (or falling) zero
crossing in the data update interval.
• Thisinstrumentdeterminesthemeasurementperiodonthebasisofthefirstrisingorfallingzero
crossing within the data update interval.
Data update interval
Measurement period
Synchronization
source
● Rising zero crossing
○ Falling zero crossing
When the Period of the Synchronization Source Cannot Be
Detected
If the total number of rising and falling zero crossings on the input signal that has been set as the
synchronization source is less than two within the data update interval, the period cannot be detected.
Also, the period cannot be detected if the AC amplitude is small. For information on the detectable
frequency levels, see the conditions listed under “Accuracy” under “Frequency Measurement” in
section 7.4, “Features,” in the Getting Started Guide, IM WT310E-02EN.
If the synchronization is set to voltage and this instrument cannot detect the voltage period, it will
detect and use the current period. If this instrument cannot detect the current period either, the entire
data update interval is used to average the sampled data.
Likewise, if the synchronization is set to current and this instrument cannot detect the current period,
it will detect and use the voltage period. If this instrument cannot detect the voltage period either, the
measurement interval is the entire data update interval.
Data update interval
Measurement period
Appendix 4 Setting the Measurement Period