
23
Reference
2. When compensation value
C
v
for effective load volume of microphone is known
Output sound pressure level
L
(dB) =
L
0
+
C
v
+ 20 × log
10
P
a
101.325
L
0
: Specifi ed sound pressure level at reference conditions (as per calibration chart,
dB)
P
a
: Static pressure at time of use (kPa)
Static pressure used for reference:
101.325 kPa
Example: Output sound pressure level
L
with UC-59
Specifi ed sound pressure level
L
s
at reference conditions:
114.05 dB (example, as per calibration
chart)
Static pressure at time of use
P
a
:
98.83 kPa (example, measured with barometer
at time of use)
Compensation value for effective load volume of microphone
C
v
:
-0.07 dB (as per table on page 20)
L
= 114.05 + (-0.07) + 20 × log
10
98.83
101.325
=
113.76 dB