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PAM1 MK2
User Handbook Issue 1
Dolby Mode:
When decoding a Dolby signal, the
Loudness
measurement feature can be set to
automatically select the appropriate audio components of the 5.1 programme. Since the
PAM1
identifies the channel configuration via the embedded
Dolby Metadata
, the Loudness feature
uses this information to define the signal under test.
2.16.2
Target Level, Limit Threshold and Red Line Alarm
The purpose of Loudness measurement is to ensure that TV programme audio content is
produced, distributed and ultimately transmitted at a level which does not inconvenience the
listener and/or contravene any local or national regulations.
PAM1
helps the broadcaster to
monitor the
Loudness
of programme audio content by comparing the measured level against a
user defined
Target Level
(this might be figure determined by a regulator). A threshold
Limit
above or below the
Target
value determines the point at which the
Loudness
value displayed
changes from green to red. The onscreen information is described below.
The
Target Level
can be set
within a range of +13 to -30 or it can be defined by the
Dialnorm
of
a decode
Dolby
signal. The value is displayed as an orange numerical value to the right of the
left LCD screen. An orange reference cursor is also displayed across the bargraphs.
The derived
Loudness
figure is indicated as a dynamic red or green numerical value using either
LKFS
or
LUFS
units of measurement. A moving cursor follows the
LFS
value as it changes
dynamically with both number and cursor changing colour from green to red as the
Target Value
plus
Limit
(if set) is exceeded.
The
Limit Value
at which a
Loudness
value ‘red lines’ can be set at up to +6 LU above the
Target Value.
At the point at which the
‘Red Line’
limit is reached,
PAM1
triggers an output
GPI
via the D15 rear connector. This can be used for external
Alarm
notification and/or to control a
third party
Loudness
control device.
Target Value
Measured
Dynamic Value
Measured Value
– Moving
Cursor
Target Value
–
Reference Line
