NSRTW_mk3
User’s Manual
8
LED State Meaning
Off
Instrument is disconnected, or is connected to a PC that is in standby.
Green
Instrument is connected to a PC or USB charger, and the battery is full.
Orange
Instrument is connected to a PC or USB charger, and the battery is charging.
Table 2
6.4.2
Operation LED
The operation LED is always blinking.
LED State
Meaning
Off
Instrument is in
Idle
mode.
1-blink/second
Instrument is in
Active
mode, but is not actively recording.
2-blinks/second
Instrument is actively recording.
1-blink/second
(off-beat)
Instrument is presently communicating with a server via
WiFi™
4-blinks/second
Battery is low. Recharge as soon as possible. If the battery level becomes critical
the instrument will go to
Idle
mode (LED-off) in order to safeguard the battery
against over-discharge as much as possible.
Table 3
6.5
Sound Level Calculation
After extracting the signal power, the calculated sound levels are low-pass filtered (smoothed) using an
adjustable time constant. This time constant is applied to the calculation of
L-min
and
L-max
, but not
Leq
. A typical short time constant (125 ms) allows the measurements to track sharp changes, while a
longer time constant (1s) provides more stable (cleaner) RMS values that averages-out short
transients.
The
Leq
is integrated linearly over the specified log interval, irrespective of the time constant setting.
The sound level statistics (
L-min
,
L-max
and
Leq
) are gathered for the specified
log-interval
before
being written to the recording memory. The log-interval represents the interval at which the selected
statistics are written to memory. Therefore a longer log-interval uses less memory, while a shorter log-
interval provides better time resolution and allows the user to distinguish between events that occurred
close together. The statistics (
L-min
,
L-max
and
Leq
) are reset at the beginning of each log-interval.
Then the statistics are gathered sample-by-sample during the log-interval. At the end of each log
interval the calculated statistics are written to memory, and the next log-interval is started. No portion of
the signal is overlooked.
The log interval is set to 1 second by default. It can be set to as short as 1/8 s.
