Dolby LM100 Broadcast Loudness Meter User's Manual

The Status Menus
The value at the far right is the largest peak value currently being measured from any
individual channel within the program. This peak meter has an instant attack, a peak hold
of 0.75 second, and a constant decay of 12 dB/second, ±2 dB/second, following the peak
hold.
The main status screen also provides different display modes. Press Enter to scroll through
these different modes on the right side of the screen.
When measuring Dolby Digital or Dolby E signals, the far right section of the default screen
shows the setting for the dialnorm value contained in the metadata stream. If you press
Enter, this section of the display shows the largest true‐peak value. If you press Enter a
second time, this section of the display shows the largest sample peak value. If you press
Enter a third time, the screen displays only a single, larger magnification of the loudness
measurement. Pressing Enter a fourth time displays the default screen where the dialnorm
value appears on the far right.
Note:
When the measurement type is ITU‐2, one additional measurement is included in
this sequence of displays (the loudness range measurement). The display sequence
repeats following this measurement screen.
Note:
When the measurement type is EBU mode, two additional measurements are
included in this sequence of displays. In addition to the loudness range
measurement, the display sequence includes a momentary maximum loudness
measurement. The display sequence repeats following this measurement screen.
If the LM100 is using the infinite method with Dialogue Intelligence enabled and dialogue
is not detected, the measurement value holds and begins to flash until the unit detects
dialogue again.
When using the short‐term method with Dialogue Intelligence enabled, if dialogue is not
detected, the measurement value flashes and a second value appears at the bottom of the
center section, as previously discussed. That value shows the current non‐dialogue‐based
measurement; the flashing value shows the last valid dialogue‐based measurement, and
the time counter in the lower left section shows the time elapsed since the dialogue‐based
measurement stopped.
When dialogue‐based measurement resumes, the time counter and the second value no
longer appear. When you select the analog input, an additional display mode is now
available. This additional mode displays the recommended value for setting the dialogue
level parameter in downstream Dolby Digital or Dolby E encoding equipment; this
recommended value allows the operator to simply calculate a dialnorm value when
measuring analog sources. Figure 4‐10 shows an example of this display.
Dolby ® LM100 Broadcast Loudness Meter User’s Manual 21