Wind screens prevent wind induced noise due to turbulence around the microphone to interfer with the measurement signal.
The frequency response will be slightly modified, and the uncertainty of your measurements will increase.
The frequency response of the combination of wind screen type Nor1451 on microphone Nor1225 and preamplifier
Nor1209 will fulfill the requirements of a type 1 sound level meter according to IEC 61672-1 when the windscreen
response compensation is turned on.
Please note that the change in frequency response due to the use of wind screens is only acceptable when
the the wind screen is intact, dry and clean.
There are different types of devises available to protect the microphone system from wind, rain, snow, dust or
other environmental influences. A microphone windscreen is a useful device for reducing the noise created around
the microphone in windy conditions. The windscreen is also useful for protecting the microphone from mechanical impacts.
Wind screens are available from different producers, in different sizes, and are usually made from reticulated foam with
different pore sizes. Therefore each type of windscreen will have a different influence on the frequency response of the
microphone system. In addition, this influence will vary over time if the windscreen gets polluted or wet, or simply is old.
Keep your windscreens in good condition, or replace them with new ones.
The spectrum of the Nor150 can be compensated for the typical influence of the Nor1451 windscreen.
Outdoor microphones use specially shaped windscreens to obtain the desired frequency response.