LMn Manual

Interface and feature reference
LM2n / LM6n Manual 18
Descriptors
The parameter values shown in the left and right
bottom corners of the LM2n/LM6n Radar page
in yellow are called Descriptors.
Universal descriptors may be used to make pro-
gram-duration measurements, or you may “spot-
check” regular dialog or individual scenes as re-
quired. It is recommended not to measure pro-
grams of a shorter duration than approximately
10 seconds, while the maximum duration may be
24 hours or longer.
The default descriptors are Loudness Range
(left) and Program Loudness (right).
Use the Settings page to select Descriptors. See
“Settings page” on page 23.
Prog. Loudness (I) descriptor
Program Loudness (I) returns one loudness num-
ber for an entire program, film or music track. Its
unit is LUFS. Some vendors and countries use
the unit “LKFS” or “LUFS”, but they are identical:
An absolute measure of loudness in the digital
domain, where the region around “0” is overly
loud and not relevant for measuring anything but
test signals. Expect readings of broadcast pro-
grams in the range between -28 and -20 LUFS.
Program Loudness is used as a production
guideline, for transparent normalizing of pro-
grams and commercials, and to set loudness
metadata in delivery if so required. For delivery
or transmission of AC3 format, the metadata
parameter “dialnorm” should reflect Program
Loudness. The easiest way to handle multiple
broadcast platforms is to normalize programs
at the station to a certain value, thereby being
able to take advantage of the normalization ben-
efits across platforms, at the same time enabling
static metadata.
Loudness measurements in LM2n / LM6n are
all rooted in ITU-R BS.1770. However, subtle dif-
ferences exist between different regions of the
world. Therefore LM2n/ LM6n also includes the
“Loudness Standard” parameter. Be sure to set
this parameter correctly for compliance in your
region.
The Program Loudness target is more or less the
same for broadcasters around the world, espe-
cially when taking the measurement differences
into account. Target numbers range between -24
and -22 LUFS.
As with Loudness Range and Loudness Max,
the meter should be reset before measuring Pro-
gram Loudness.