YOKOGAWA WT333E - Page 60

4-6
IM WT310E-01EN
Frequency Measurement Ranges
• Themeasurementrangevariesasshownbelowdependingonthedataupdateinterval(seesection2.10).
Data Update Interval Measurement Range
0.1 s 20 Hz to 100 kHz
0.25s 10 Hz to 100 kHz
0.5s 5Hzto100kHz
1 s 2.0 Hz to 100 kHz
2 s 1.0 Hz to 100 kHz
5s 0.5Hzto100kHz
10 s 0.2 Hz to 100 kHz
20 s 0.1 Hz to 100 kHz
Auto* 0.1 Hz to 100 kHz
* If the data update interval is set to Auto, the lowest measurable frequency is as follows
depending on the timeout setting (see section 2.10).
TImeout Lower Frequency Limit
1 s 2.0 Hz
5s 0.5Hz
10 s 0.2 Hz
20 s 0.1 Hz
• Thisinstrumentautomaticallyswitchesbetweenthefollowingsixmeasurementranges:1Hz,10
Hz, 100 Hz, 1 kHz, 10 kHz, and 100 kHz.
• TheWT332E/WT333Esimultaneouslymeasuresthevoltagefrequencyandthecurrentfrequency
of the element selected in display D.
Input Element (WT332E/WT333E only)
The elements that you can select vary depending on the model. Check the model when selecting elements.
• 1,2,or3:Displaythemeasuredvaluesofelement1,2,or3.
• Σ:Forthedisplaywhenthephaseangleisbeingmeasured,seesection4.1.Whenthefrequencyis
being measured, hyphens (------) are displayed instead of measured values.
Note
Phase Angle
• Evenwhentheinputsignalisthesame,thedisplaymaychangeifyouchangethemeasurementmode
(RMS,VOLTAGEMEAN,orDC).Fordetailsonmeasurementmodes,seesection2.1.
• Wheneitherthevoltageorcurrentfallsto0.5%orless(1%orlessifthecrestfactorissetto6or6A)of
the measurement range, the phase angle will be displayed as an error (“Error”).
• Aproperdistinctionbetweenphaselagandleadcanonlybemadewhenboththevoltageandcurrentaresine
waves and the ratios of the voltage and current input to the measurement range are not significantly different.
• Whenthepowerfactorisgreaterthan1,thephaseangleisdisplayedasfollows.
• Whenthepowerfactorisbetween1.0001and2.0000,thephaseangleisdisplayedas0.0.
• Whenthepowerfactorisbetween–1.0001and–2.0000,thephaseangleisdisplayedas180.0.
• Whenthepowerfactorisgreaterthanorequalto2.0001orlessthanorequalto–2.0001,thephase
angle is displayed as “Error.”
Frequency
• 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 chapter 7, “Features,”
in the Getting Started Guide, IM WT310E-02EN.
• Thisinstrumentmeasuresthefrequencybysynchronizingwiththecycleoftheinputsignal.We
recommend that you enable the frequency filter when measuring an inverted waveform or a waveform
with a high noise level. However, depending on the signal’s frequency and level, the frequency may be
displayedas“Error.”Thisisbecausethefilter,whichhasacutofffrequencyof500Hz,mayattenuatethe
signal to a level at which no input signal is recognized.
• Evenwhenthefrequencyfilterisdisabled,thefrequencymaybedisplayedas“Error”ifthefrequencyis
greater than the measurement range and the internal circuit attenuates the signal to a level at which no
input signal is recognized.
4.3 Displaying Phase Angles and Frequencies