Norsonic nor118, Instruction Manual

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20 Chapter 4
Simple sound measurements
21 Norsonic Nor118
User Guide
Resuming an ended measurement
Assume that you have set up the instrument to measure
for  minutes and that you start the measurement. After 
minutes the measurement will end since the measurement
time elapsed equals the preset duration. e measure-
ment has now ended successfully, as opposed to if you
press the  key to forcefully terminate an ongoing
measurement.
If you now press the / key, the instrument
will resume the measurement and go on measuring for
another  minutes so that the total measurement time
assumes  minutes, i.e. twice the initial setting. If you do
this again, the total measurement time will be  minutes,
i.e. three times the initial setting and so on.
is way of prolonging a measurement will not activate
the back-erase feature (see below for more on this).
The back-erase feature
When you press the / key during an ongo-
ing measurement, the instrument will temporarily halt
the measurement. Pressing the key again will cause the
instrument to resume the measurement while at the same
time erasing the data acquired during the last  seconds
immediately preceding the pause.
If the measurement has been running for less than 
seconds when you press the / key, the entire
measurement will be erased upon resuming the measure-
ment.
If less than  seconds have elapsed since the last time
you resumed a paused measurement, only the part of the
measurement acquired since the last resume will be erased.
Data acquired earlier are assumed to be accepted by you.
e measurement time elapsed counter will be updated
to reflect the back-erase. Note that the statistics buffers
(optional extension) will be updated similarly.
Displaying the functions measured
e instrument measures the , 
MAX
, 
MIN
, 
eq
, 
E
and the 
PEAK
. Note that the , 
MAX
and 
MIN
are all
measured with the selected time constant while the rest
do not make use of the time constant at all.
During measurements the  value is updated every
second. Once the measurement is over, the  becomes
meaningless. A single  value cannot be used to char-
acterise the measurement unless it represents some kind
of maximum, minimum or time-integrated average. It is
thus not accessible post measurement.
To return to  mode, i.e. how the instrument
behaved before the measurement was started press the
 key. You will be prompted to store the data or press
The functions are available sequentially
To display a certain function, press the  key
repeatedly until the function appears. e sequence
is as follows:
SPL*
Leq Lmax
Lmin
L
E
Lpeak
*Accessible during measurement only – not after!
FUNC