YOKOGAWA WT210 User Manual page 124

Averaging Function
Output to an External Plotter
Effect of Aliasing
IM 760401-01E
Overrange Dislay
The overrange display (being the same as for normal measurement; see section 2.3)
will appear when all rms values of the 1st to 50th order reach the following value:
• Greater than equal to 140% of the rated range for voltage measurement range 600
V or current measurement range 20 A
Greater than equal to 140% of the rated range for voltage measurement range 300
V or current measurement range 10 A if the crest factor is set to 6
• Greater than 200% of the rated range for voltage measurement ranges other than
600 V or current measurement ranges other than 20 A
Greater than equal to 200% of the rated range for voltage measurement ranges
other than 300 V or current measurement ranges other than 10 A if the crest factor
is set to 6
The relative harmonic content and harmonic distortion are related to voltage and
current.
Error Display
The power factor or phase angle will show PFErr or dEGEr when either the voltage,
range or power exceeds 200% of the range.
Computation Over Display
Appears in the same way as for normal measurement.
Measurement Abort/No Data Display (Bar Display)
The display will show bar in any of the following cases.
• When there are no more measured data to be displayed during harmonic measurement;
• Soon after the harmonic measurement function has been turned ON;
• When the PLL synchronization is being re-established;
• Until the initial measured data are obtained, after having changed the settings;
• When the analysis order which depends on the fundamental frequency, exceeds
the upper limit, after having set the order at display A;
• When the display function is set to relative harmonic content (%) and the order at
display A is set to 1;
• When the PLL source is set to voltage, and an attempt is made to display the
current frequency (AHz); or when the PLL source is set to current, and an attempt
is made to display the voltage frequency (VHz);
• When an element which is not assigned to the measurement object, is selected.
However, since the frequency is not related to the element setting, the fundamental
frequency designated as the PLL source can be displayed.
Exponential averaging is performed with an attenuation constant of 8.
Using the GP-IB or serial interface, harmonic measurement data can be printed as value
or graph on an external plotter.
This instrument is not equipped with an internal aliasing filter. Due to aliasing accidental
errors may occur under the following circumstances.
Fundamental frequency f in Hz
40 ≤ f < 70
When harmonic components of the 256th or higher exist;
70 ≤ f < 130
When harmonic components of the 128th or higher exist;
130 ≤ f < 250 When harmonic components of the 64th or higher exist;
250 ≤ f ≤ 440 When harmonic components of the 32nd or higher exist.
7.1 Harmonic Measurement Function
7
7-3