Tektronix WFM5200 & WVR5200, How-To Manual

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How to Guide Audio Loudness Monitoring
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Function Description
Meter Scaling
You can change the range and limits of the Audio bar display in the
Meter Scaling menu. The meter scaling choices are:

Normal

Custom Height

Custom Offset

Graticule Step Size
If you use the Normal settings, then you will see 70 dB of range for the
bars. For digital input, the top of the scale will be DBFS, and for analog
inputs it will be dBu.
If you chose the
Custom Height settings, then you can reduce or
expand the range. If you choose the Custom Offset setting, then you
can shift the displayed levels up and down. Together, these allow you to
zoom in on one region or shrink the bars to cover a large range.
If you select
Graticule Step Size , then you can select spacing between
graticules and labels on the display. For example, at a value of 6 there
will be a label at 0dB, -6dB, -12dB, and so on.
Alarm Thresholds
Audio Loudness configurable Alarm Thresholds are:

Channel Loud : The loudness level threshold for a single channel,
audio source, above which the loudness value triggers an alarm
condition.

Program Loud : The loudness level threshold for all channels used
by the Loudness measurement, above which the loudness value
triggers an alarm condition. This alarm will trigger an in-bar audio
message of Too Loud.

Program Quiet : The loudness level threshold for all channels used
by the Loudness measurement, below which the loudness value
triggers an alarm condition. This alarm will trigger an in-bar audio
message of Too Quiet.

Target/DN Delta : When the difference between the Target loudness
level threshold and the current Dialnorm value exceed the user
defined setting an alarm will be triggered.
Target Loudness

High

Low
The Target Loudness of an audio program is defined as the specified
value for the Anchor Element (Dialog Level), established to facilitate
content exchange from supplier to operator.
The Anchor Element is the perceptual loudness of a reference point
element around which other elements are balanced in producing the
final mix of the content, or that a reasonable viewer would focus on
when setting the volume control, as defined in ATSC standard A/85.
The default value within the instrument is -24LKFS and is user
selectable.
High and Low thresholds are defined above and below the Target
Loudness value.
The default values are 2LU (+/-2LKFS) above and below the Target
Loudness.
For detailed information on the ATSC A/85 standard visit
www.atsc.org .