18
Reference
Output sound pressure level compensation using supplied barometer
The barometer supplied with this unit is a Class LS/C device that can be used to provide
compensation of the sound pressure level for a static (atmospheric) pressure range of 905
hPa to 1055 hPa (90.5 kPa to 105.5 kPa).
Place the barometer on a level horizontal surface and lightly tap it with your fi ngertip to
stabilize the needle.
When using the pistonphone, read the current
static (atmospheric) pressure from the scale of
the barometer and insert the value into Equa-
tion 3 (page 17) to calculate the output sound
pressure level with compensation.
Note
The barometer is a precision mechanical
instrument. Do not tap it too forcefully, and
make sure not to drop it.