22
Reference
Output sound pressure level compensation (example)
In actual use, the output sound pressure level generated by the pistonphone is calculated
by applying compensation for the microphone effective load volume (differs according to
microphone type) and the static (atmospheric) pressure. The output sound pressure level
L
(dB) is therefore obtained as follows.
1. When specifi ed sound pressure level
L
s
(as per calibration chart) is known
Output sound pressure level
L
(dB) =
L
s
+ 20 × log
10
P
a
101.325
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
Specified sound pressure level
L
s
: 113.98 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)
L
= 113.98 + 20 × log
10
98.83
101.325
=
113.76 dB