4
Microphone Polarisation
Microphones require a polarisation voltage to operate and are manufactured in two
ways.
Externally Polarised
These microphones require an external charge for the microphone to operate which
is generally 200V and supplied by the sound level meter.
Pre-Polarised
These microphones generate the polarisation voltage internally and do not require the
externally generated 200V polarisation charge.
All microphones supplied with SONIK sound level meters are
Pre-Polarised
.
Microphone Sensitivity
The sensitivity of a microphone is determined by the output voltage it produces for a
defined sound source.
Microphones are manufactured with numerous sensitivity levels and operate within a
specified tolerance. Different microphones of the same model may therefore give
slight differences in readings when used on the same sound meter. To allow for this
all SONIK sound level meters have been designed to accommodate any variations in
the tolerance of the supplied microphone up to ±3dB.
All models of the SONIK sound level meter have been designed for microphones with a
sensitivity of 25mV/Pa.
Great care must be taken to ensure the microphone and sound meter sensitivities
match otherwise incorrect readings will occur.
