User manual

294
Appendix
Slow Time Weighting
Time constant t = 1 second; the time-weighting is
an exponential function of time, which defines how
changes of the instantaneous sound pressure level
are averaged for useful sound level results. The de-
cay rate is 4.3 dB/s.
Parameter T3
Clock-Impulse Maximum Level (Taktmaximalpegel)
L
AFT3
in accordance with DIN 45645-1.
Maximum sound pressure level measured with fre-
quency weighting A and time weighting F within a
time interval of 3 seconds.
Parameter T3eq
Time-average Clock-Impulse Maximum Level
(Taktmaximalpegel) L
AFT3eq
in accordance with
DIN 45645-1.
Parameter T5
Clock-Impulse Maximum Level (Taktmaximalpegel)
L
AFT5
in accordance with DIN 45645-1.
Maximum sound pressure level measured with fre-
quency weighting A and time weighting F within a
time interval of 5 seconds.
Parameter T5eq
Time-average Clock-Impulse Maximum Level
(Taktmaximalpegel) L
AFT5eq
in accordance with
DIN 45645-1.
Inverted X-Curve
In the film and recording industry an X curve is also
known as a wide-range curve, e.g., used for cinema
installations conforming to SMPTE ST 202:2010 or
ISO 2969:2015 @ 500 seats.
Z-frequency weighting in accordance with IEC
61672 (= flat frequency response, no filter)
Overall sound pressure level, all sound signal com-
ponents are included; required for special applica-
tions.