Brüel & Kjær 2240 Guide De L'utilisateur page 28

22 Integrating-averaging Sound Level Meter Type 2240 – User Guide
6) Under-range indicator: Any sound detected during the measurement that is 0.5 dB or
more under the bottom end of the measurement range prompts the indicator. You may want
to change the measurement range to the lower level (30 – 110 dB), if applicable, by pressing
, otherwise your measurement results will reflect under range conditions.
7) Calibration value: When you press
the instrument. The calibration value is based on the sound level range Type 2240 is pres-
ently set up to measure (30 – 110 dB or 60 – 140 dB). Use the included screwdriver to adjust
your instrument to match this value.
8) Overload indicator: Sounds detected are 0.3 dB or more over the upper end of the meas-
urement range. If an overload has occurred in the last second,
black background. If an overload has occurred at any time during a measurement in
progress, then the word Over has a plain background – this is called a latched overload.
Latched overloads are cleared with the start of a new measurement and are not applicable
with the L
A
You many want to change the measurement range to the higher level (60 – 140 dB), if
applicable, by pressing
ditions.
9) Parameter display: Shows the type of sound level reading displayed (L
)
L
Cpeak
10) Sound pressure level value: The sound pressure level applies to the current parameter
being displayed. It is updated once per second.
11) Battery level: When the batteries are new, this indicator displays two black level columns.
As the batteries are used, the level falls. Replace the batteries when this indicator is empty
and flashing.
12) Peak or Time weighting: Peak is displayed together with the L
the peak level for this parameter is displayed. Fast is displayed with L
rameters to denote that the 'F' time-weighting is used.
Measurement Start and Stop
When you switch on the instrument, the instantaneous sound pressure level is displayed (L
Monitoring the L
While L is automatically measured, calculation of the other three parameters (L
AF
and L ) must be initiated by pressing
Cpeak
the upper left-hand corner of the display flashes to denote calculations are being made.
Throughout the measurement time, you can view the various sound level parameters and their
current values by scrolling through the parameter menu
The flashing arrow
All results are cleared when the instrument is switched off.
parameter.
, otherwise your measurement results will reflect overload con-
for a short period gives you an idea which sound level range to choose.
A
in the display stops.
for 3 seconds, you start an electrical calibration of
C
. Once a measurement is started, the arrow
. To stop a measurement, press
is displayed with a
, L , L , or
A Aeq Amax
parameter to denote that
and L pa-
A Amax
).
A
, L
Aeq AFmax
in
.