Sigicom 080-02850-0, Руководство пользователя, Страница: 14 / 36

12 Copyright ©Sigicom AB 2003-2014
3.6 Interval files
L
max/
L
peak
and L
eq
data are saved in separate files, named interval
files. For traceability of the registrated data, all files have an
extensive header where all necessary meta-data is saved. Attached to
each saved data there is information about overload, invalid data and
registration status changes.
3.7 Transient file
The S50 records a transient file ( sound clip ) after a trigger event. The
trigger event is fired when any of the following is valid:

The sound pressure level in the L
max
/L
peak
channel becomes
larger than the threshold level, and the threshold is
activated.

Another sensor connected to the same Datalogger triggers.

The operator of the Datalogger fires a manual trig.
.
Recording post-trig length is adjustable between 1 and 10 seconds.
Pre-trig is always 1 second.
Transient data:

The microphone signal is tapped from the signal chain after
the dBA or dBC filter, but before the RMS/PEAK detector
to enable post-processing.

Before the signal is saved in the transient file it is low-pass
filtered (-3dB at 1.5kHz) using a FIR filter and down-
sampled to 4096 Hz.
Limitations of possible amount of recordings:

The transient memory in the S50 has a length of 11 seconds,
and must be transferred to the Datalogger before a new
transient can be recorded.

In order to enable long cables and low power of the
communication, the transfer capabilities between S50 and
the Datalogger are rather slow. It transfers approx. 0.15 s of
S50-data per second or 0.4 s of vibration sensor data per
second.