The upper left corner of the display shows the wow and flutter reading,
which is the amount of fluctuation in the frequency of the incoming
tone. The only available unit is percent. Ifthe input frequency is
below 2.8 kHz, the display will read ‘Lo Fr’ (low frequency). If the
input frequency is above 3.35 kHz, the display will read ‘Hi Fr’ (high
frequency). No valid W+F readings can be obtained outside of this
frequency range.
The upper center section ofthe display shows the level (amplitude) of
the incoming signal. The upper center soft key selects among the usual
set ofabsolute and relative amplitude units.
The upper right section ofthe display shows the frequency ofthe
incoming signal. This should be approximately 3 kHz or 3.15 kHz,
depending on the frequency of the test signal. The upper right soft key
permits measurement ofthe percent deviation from the ideal. The
units change to ‘
∆
%’ and the top part ofthe display shows the
reference frequency, either 3 kHz or 3.1 kHz. Additional presses on
the upper right soft key will cycle through the absolute frequency
display and percent deviation for each of the available reference
frequencies.
The lower left soft key allows selection of a weighting filter that
approximates the ear’s sensitivity to wow and flutter. The ‘WTD’
selection uses this filter; the ‘UN-WTD’ selection bypasses it, for a flat
response. All the major wow and flutter standards recommend use of
this weighting filter.
The lower center soft key selects the standard to which the
measurement is made. Presses ofthe key will cycle through IEC, NAB,
and JIS standards. The DIN standard is identical to the IEC standard.
The different standards require different test tone frequencies and
detector response characteristics. The generator frequency is changed
to the tone frequency required by the selected standard, and the
proper detector response is selected.
The lower right soft key selects the reading display mode. PEAK and
2
σ
are supported. Selecting PEAK will give the maximum value ofthe
wow and flutter over about a 1/3 second interval. Selecting 2
σ
will
give the maximum value exceeded no more than 5% ofthe time (the
second-highest reading ofa 20-reading group).
&
For more
information on
amplitude units,
see page 4-71.
4
Oper
ati
o
n
Controlling the Analyzer : W+F (Wow andFlutter)
Operation
Portable One Plus Access User's Manual
4-49
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
