16
measurements
17
basics
Sound Level
measurements
Sound Level
10
100
1000
10000
-60
-40
-20
0
W
eighting (dB)
Frequency (Hz)
A-weighting
C-weighting
Relative Sensitivity of Human Ear (60 phons)
How do I measure current sound
levels with the soundBadge?
Press
to advance to the
LEVEL
page. If
MAX
or
AVE
is displayed press
until you remove them.
Press and hold
to cycle through
to the combination of frequency
weighting (A, C, or no weighting) and
time constant (fast = 1/8s or slow =
1s) you require.
A small ‘
F’
or a large
‘S’
is
displayed to indicate a fast or slow
time constant; while an ‘
A
’ or ‘
C
’ are
displayed for A and C weightings.
If neither A nor C is displayed, no
frequency weighting is applied (oft en
called Z-weighting).
How well does the soundBadge
measure sound levels?
Th
e soundBadge measures A, C, and
Z-weighted sound levels from 55 dB
to 140 dB with a 0.1 dB display resolution.
When calibrated, the levels are within
+/- 2.0 dB of acoustic values from 63 Hz
to12 kHz or better. In accordance with
sound metering standards, the soundBadge
can measure sound levels using a ‘fast’
response mode (1/8 s time constant—an
‘
F
’ is displayed) or a slow mode (1s time
constant—an ‘
S
’ is displayed). For most
measurements, the slow mode is preferable.
What is sound level?
Sound level is a quantity proportional to acoustic power. Several diff erent sound level
measurements can be made. Th
e diff erence between these measurements is the diff erent
way they weight various frequency components. Th
e most commonly measured sound
levels are the ‘A-weighted’ sound level, which mimics the sensitivity of the ear at low
to moderate sound levels, and the C-weighted sound level, which spans the range of
human hearing and mimics the ear’s sensitivity at high sound levels. Th
e soundBadge
measures both of these and also measures Z-weighted or ‘fl at’ frequency response. Use
A-weighting when measuring low-level sounds (55-100 dBA) and use C-weighting for
high-level sounds (100-140 dBC).
