Norsonic nor140, Instructional Manual

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Norsonic Nor140
Instruction Manual
Trigger
General
Noise monitoring often requires operating a sound
level meter out in the field for unattended long-term
measurements. The trigger option (option 16) allows
the measurement to start when a selected condition is
satisfied. The condition may be:
• A certain time of the day
• An externally supplied trigger signal is activated
• Level is above a specified threshold
By using the clock trigger, a measurement may be
started at a specified time of the night even if the instru-
ment is set up during daytime. The result may be stored
automatically, the instrument can be picked up later and
the results downloaded.
By setting the storing option to “Repeat” a meas-
urement may be started automatically each day at the
same time. Ensure that the measurement time is se-
lected so the measurement is terminated before a new
trigger condition is satisfied.
The measurement may also be initialised by a trig-
ger signal from an external device. When started, the
measurement will last as long as set up by the meas-
urement duration parameter. By using the storing op-
tion “Repeat”, a new measurement may be started by
a new trigger signal after the first is finished.
The external trigger option may be used for syn-
chronising more sound level meters.
An often-used trigger function is the threshold trigger,
which starts a measurement as soon as the noise level
exceeds a pre-defined level. Used in combination with
the repeat function and automatic storing of the result,
the sound level meter may unattended store a number
of noise events for later analysis.
The triggering of sound records are covered in the
section
“Recording the sound”.
Setup menu Trigger menu
Triggering a sound record
The triggering of sound records are cov-
ered in the section
“Recording the sound”.