RTW MM3 Bedienungsanleitung Seite 162

If MC has been selected in the menu as Active instruments instead of
PPM, Moving Coil instruments with two selectable scales are available:
Loudness Chart (Loudness over
time), MC (2-channel) with British
IIa scale, Loudness bargraph verti-
cal (M, S, I selectable), control keys
for Loudness and Time for Chart
EN-42 4 | Displays | 4.1 | Selectable views
Loudness Chart (Loudness over
time), MC (2-channel) with VU
scale, Loudness bargraph vertical
(M, S, I selectable), control keys for
Loudness and Time for Chart
Manual | MM3 MusicMeter