Tektronix WFM5200 & WVR5200, How-To Manual

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How to Guide Audio Loudness Monitoring
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Function Description
Loudness Filter/Measure
The Loudness Filter and Measurement selection controls which of
the three weighting filters are applied to the audio loudness
measurement, and is used by the loudness algorithm to calculate the
audio loudness.
Selections for this parameter are:

LKFS (ITU-R BS.1770) - LKFS measurements using the K-weighting
filter as specified by ITU-R BS.1770. This filter is preferred for
surround sound programs, and is specified by ATSC and EBU
recommendations for monitoring program loudness.

Leq (Linear) - Leq measurements using a weighting filter with a flat
response.

Leq(A) - Leq measurements using the A-weighting filter, which more
closely matches the frequency response of the human ear.
The filter selection applies to several areas:

The Surround Sound display

The Bar displays when displaying the loudness ballistic

The Program or Channel Pair audio loudness bar displays

Loudness measurements and readings in the Audio Display, Audio
Session Display, Audio Loudness Display, and Dolby Status
Displays.

The Audio Loudness Session display
The currently selected filter is shown within the Audio Display above the
Loudness Bar or within the Surround Sound display.
Momentary Integ. Time
Average Integ. Time
The Loudness Filter & Measure menu has the following selections.
Loudness Filter:
LKFS (ITU-R BS.1770) Loudness weighting filter that complies with ITU-
R BS.1770 standard.
Leq (Linear) Linear Loudness weighting filter that has a flat response.
Leq(A) A-Weighted Loudness filter that has a response that closely
matches the frequency response of the human ear.
Momentary Integration Time:
IEC 62672 (125ms) Integration time of audio bars is set to 125ms
EBU R/128 (400ms) Integration time of audio bars is set to 400ms
Average Integration Time:
This value sets the Short duration over which the time interval is set for
the Loudness Average.
The range for this setting is from one second to 60 seconds. The default
value is 10 seconds.