The Casella 490.B2 Octave Band Sound Level Meter Kit is the ultimate instrument for long term community noise measurements where wide changes in levels are expected to occur. Previous generations of noise meters require the user to make a decision on the likely noise levels to be expected during the measurement. Select too high a range and the low background levels will be missed. Choose to low a range and the important peak levels will cause overloads and consequent errors. The single 140 dB range available in the CEL-490 enable worry free measurements over the whole audio range without changing range. A wide range and all the frequency information collected simultaneously with the power of DSP filters.
The Casella 490.B2 Octave Band Sound Level Meter Kit comes into its own for difficult noise applications
when rapid data recording is required. Spectral data capture as fast as 10
millisec per octave or third octave band spectrum ensures that even the most difficult transient sounds will be measured correctly with no loss of acoustic data integrity.
|
Octave and third octave
band
measured parameters: |
Instantaneous level Lxy,
maximum level Lxymx, minimum level Lxymn,
average level Lxeq, peak level Lxpk, 5 user selectable LN% values |
|
Acoustic accuracy: |
ANSI S1.4 (R1997) type 2,
IEC 61672:2002, IEC 60651 :
1994, IEC 60804 : 2000, IEC 61260 : Class 0 |
|
Frequency response (Hz): |
6.3 Hz to 30 kHz for -3 dB down points |
|
Octave band center
frequencies: |
11 simultaneous bands with center
frequencies 16 Hz to 16 kHz |
|
Third octave band
frequencies: |
33 simultaneous bands with center
frequencies 12.5 Hz to 20 kHz |
|
Time weightings (response): |
Slow, Fast and Impulse for rms. |
|
Peak frequency weighting: |
'A', 'C' or 'Z' separate from
rms. weighting |
|
Dynamic range for
calculations: |
140 dB |
|
Noise floor (dB): |
16.5 'A' weighted, 19.7 'C'
weighted, 23.4 'Z' weighted |
|
Maximum noise level (dB): |
140 dB rms., 143 dB peak (with standard 50
mV/Pa CEL-250 mic) |
|
Resolution (dB): |
0.1 dB across whole range |
|
DSP sampling rate (Hz): |
67,200 Hz sampling with true rms. values
calculated digitally |
|
Histogram classwidth (dB): |
143 x cells at 1 dB steps
for full 140 dB range plus over-range and
under-range cells (user selectable for broadband measurements) |
|
Memory storage capability: |
2 Mbytes (over 800,000 data points) 25,000
full octave spectra |
|
Sampling intervals, in
periods up
to 14 parameters (user selected): |
19 times from 10, 20, 50,
100, 250, 500 msec 1, 5, 10, 15, 20, 30 sec
1, 5, 10, 15, 20, 30, 60 min |
|
Sampling intervals, up to 4
time
history profiles (user selected): |
18 times from 10, 20, 50,
100, 250, 500 msec 1, 5, 10, 15, 20, 30 sec
1, 5, 10, 15, 20, 30 min (profile interval time must be ¡Ü period
times) |
|
Fixed duration for
measurement: |
12 durations from 1, 5, 10, 15, 20, 30 min
1, 2, 4, 8, 12, 24 hour |
|
Delayed start and stop for
runs: |
Up to 7 pairs of delayed timers can be set
up to 30 days in advance |
|
Calibration method: |
Manual or automatic set to
user entered dB level, last 4 calibration
details saved for review and verification of stability |
|
Configurations saved in
memory: |
1 factory default plus 4 user setups saved
per bandwidth |
|
Analog outputs: |
AC signal 0.5 V rms. at 94
or 114 dB FSD
(plus optional log DC output 0 to 2 V for 0 to 140 dB at 14.28 mV/dB) |
|
Digital output: |
Download or remote control of operations
of meter via dB23 software |
|
Baud rate for digital
transfer: |
8 settings from 9600 to 115200 baud |
|
Screen languages: |
English, French, German, Italian, Spanish
menu selectable |
|
LCD screen display: |
128 x 64 pixel monochrome backlit display
with icon indicators |
|
Size: |
13.4 x 4 x 1.5 in (340 x 100 x 40 mm) |
|
Weight: |
19.3 oz (550 gm) |
|
Tripod socket: |
Standard camera thread (1/4 inch) |
|
Internal power supply: |
4 off AA alkaline cells (15
hours typical max battery life for
broadband, 12 hours typical for narrow band measurements) |
|
External power supply: |
12 V dc at 150 mA nominal via 2.1 mm power
connector |
