Norsonic nor118, Инструкция по эксплуатации

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78 Chapter 16
Noise monitoring
79 Norsonic Nor118
User Guide
of whether termination took place because the duration
expired or because you pressed .
• R, which causes the instrument to store the
acquired data and then restart immediately and make
another measurement using the same measurement
setup and duration. Repeat applies to measurements
terminated by themselves only. If you terminate a
measurement by pressing , the instrument will
not restart. Note that some time will be spent on stor-
ing the acquired data, erefore a slight delay (typically
– seconds) in the restart moment will be observed.
• S, which compensates for the time spent on
housekeeping (i.e. storage of data etc.) to maintain
synchronisation with the time of day. is works in
the way that the instrument synchronises itself with
the full hour of the time of day. To be active, 
requires a minimum measurement time (duration) of
 seconds per individual measurement.
Synchro – an example
Assume that you set up the instrument to measure in
periods of one hour and that you start the measurement
at ::. e first period will be truncated and last a
little less than  minutes and  seconds (it will last for
 minutes and  seconds to be exact) to give room for
storage before ::. e succeeding period will then
each be very close to an hour long to enable restart again
at ::, :: etc.
Now, what happens if you select a period duration
whose multiples fail to match one hour? If you set up the
period duration to, say  minutes, and start the measure-
ment, the instrument will measure in periods of  minutes
and  seconds to enable a restart exactly  minutes after
the previous period started.
However, the first time the full hour is reached, one
period will be truncated (if needed) to lock the measure-
ment onto the full hour at least once. e odd choice of
period length will, however, fail to make the full hour
synchronisation work in a sensible way. e principle has
been designed with period lengths of an hour, half an
hour,  minutes etc. in mind.
Going to measure very high levels?
As an optional extension the Nor118 is
able to measure very high sound pressure levels
without changing the microphone cartridge – see
High levels in the Technical specifications for details.
Keyboard lockout –
l
ocking the
keyboard to prevent unauthorized
operation.
You may lock the keyboard to prevent
the instrument from being tampered with while it
is left on its own.
To lock the keyboard:
Press | ←, →, → |, ← to lock the keyboard
To unlock a locked keyboard:
Press ←, → |, →, | ← to unlock the keyboard
Note that the instrument must show the sound level
meter display for this to work (in this display the
 keys are not used).