Norsonic nor118, Instruction Manual, Page: 47 / 116

34 Chapter 5
Frequency analysis
35 Norsonic Nor118
User Guide
Basic time profile
measurements
I
  with the optional extension ,
level vs. time will be able to log the time profile like the
classic level recorders used to do.
e time profile is measured by dividing a measurement
into smaller periods of time, all having the same duration.
Extension 6 allows the period length to be from 1 second
and upwards in 1 second steps, while the enhanced profile
(the optional extension ) allows a period length from
100 ms and upwards in 25 ms steps (but in 1 second steps
above 1 second period length).
Global vs. profile
e traditional sound level measurement and the fre-
quency analysis both consider the entire measurement
as a whole without dividing it into smaller parts. One
may therefore consider these two measurements as global
measurements, while the level vs. time measurements
represent the profile .
In the display the global measurements are denoted Σ
(pronounced sigma ) while the profile measurements are
denoted ∆ (pronounced delta ). To switch between the
modes, just press the Σ↔∆ key.
e 
eq
is measured for every period separately and
stored in a buffer. Likewise, the 
MAX
and 
MIN
and the

PEAK
are measured for every period. All functions are
-weighted apart from the peak level which can be set as
-or -weighted. e enhanced profile (ext. 7) provides
more options – see Enhanced profile measurements .
Profile measurements may be made in parallel with
global frequency analysis (filters are optional) and in paral-
lel with the traditional sound level measurement described
in the chapter Simple sound measurements . If your Nor118 is
The time profile is no less than an electronic level recorder!