NSRTW_mk3
User’s Manual
9
Note:
The time constant only affects the calculation of Lmin and Lmax. The Leq is integrated linearly
over the specified log interval.
6.6
Manual Recording
Every time a recording is started, a new record is created in memory and filled until the recording is
stopped. That record is time-stamped, so the signals can be displayed with respect to absolute
date/time. Records are stored sequentially in the instrument’s memory. There is no limit to the number
of records that the memory can contain, only a limit to the total size of the data recorded. The
Instrument_Manager
application displays the total memory recording time as a function of the various
setup parameters.
After (or while) recording, the records contained in memory can be downloaded from the instrument
and observed or exported. In case a recording is ongoing the last record is only displayed up to the
present time.
The recording is stopped automatically when the recording memory is full. This way a new record will
not overwrite an old one.
The recording memory is non-volatile, so there is no risk of losing the data that has already been
recorded, even in the case of a reset or battery failure.
Note:
It is perfectly legal to find empty records in memory. That occurs typically when a recording is
started and stopped quickly (for a time shorter than the log interval), before any data had time to be
written to memory. In that case only the time-stamp is written to memory.
An empty record can also occur when a recording was started but no data (Lmin, Lmax or Leq) was
selected to be recorded.
To record sound levels proceed as follows:
1. Select the statistics to be recorded (
L-min
,
L-max
and/or
Leq
).
2. Select the log-interval. Note that the total recording time is automatically calculated and
displayed by the
Instrument_Manager
application, as a function of the log-interval and statistics
selected. The log-interval is adjustable in 125 ms increments, from 125 ms up to 2H.
3. Select the time constant used to smooth the measured sound levels for
L-min
and
L-max
.
Choose the Fast time constant (125 ms) to be able to detect short peaks and valleys. Choose
the Long time constant (1 s) to provide cleaner more stable sound levels. Or adjust to another
value, as required by the application.
4. When ready to start a recording immediately, simply press the
Record
button. Press
Record
again to stop the recording.
5. Or to set a start time/date:
•
Check to make sure that the instrument time is correct. If that is not the case press the
Sync button in order to automatically set the instrument time to the PC time.
•
Press the
Timer
button. Set a start time and date using the calendar.
•
Click OK to arm the trigger.
