Outdoor microphones

Unprotected measurement microphones are sensitive to environmental factors such as wind, rain and snow. This shortcoming has been eliminated by specially designed units that protect the microphone. GRAS offers two types;

  • Permanent Outdoor Microphone Systems that are designed to be part of permanent noise surveillance systems, i.e. for airport and community noise surveillance.They can withstand all weather year after year. They are equipped with four-pronged anti-bird spikes on top of the windscreen. This prevents birds from perching on top of the windscreen when the microphone unit is placed outdoors for long-term unattended noise surveillance. Birds perching on top of the windscreen can seriously disturb measurements or even overload the measurement equipment. Furthermore, bird excreta can distort the acoustic properties of the windscreen so that it no longer performs according to original specifications. Some smaller birds have actually been known to nest on top of the earlier three-pronged anti-bird spikes. Hence, the introduction of a fourth, centre prong.
  • Outdoor Microphones designed for unattended outdoor use for very long periods. They have state of the art weather protection. Extensive use of high-grade stainless steel enables them to withstand a wide range of weather conditions and temperatures for a very long period, i.e. easily a year or longer. The protection grid is a special design that offers added water protection. The wind screen eliminates the effects of air flow and also serves as part of the water protection. In addition to its acoustical function, the top cone acts as a bird spike.

Both types are available with 0° incidence for airport noise monitoring and 90° incidence for community and traffic noise monitoring. All GRAS versions comply with the relevant international standards for noise monitoring.

GRAS outdoor microphones are among the range of special microphones that furthermore includes 

GRAS 41AC-2 LEMO Outdoor Microphone with RemoteCheck for Community and Airport Noise

Standard: IEC 61672-1
Special features: RemoteCheck
Configurable for 90 or 0 degrees of incidence
IP55 proof

GRAS 41AC-2 LEMO Outdoor Microphone with RemoteCheck for Community and Airport Noise

The 41AC-2 is an outdoor microphone for unattended use for prolonged periods of time. It can be used for community noise applications or for monitoring of overhead aircraft noise. It has RemoteCheck for monitoring of the mesurement chain...

GRAS 41AC-3 CCP Outdoor Microphone for Community & Airport Noise

Standard: IEC 61672-1
TEDS
Special features: Configurable for 90 or 0 degrees of incidence
IP55 proof

GRAS 41AC-3 CCP Outdoor Microphone for Community & Airport Noise

The 41AC-3 is an outdoor microphone for unattended use for prolonged periods of time. It can be used for community noise applications or for monitoring of overhead aircraft noise...

GRAS 41AC-4 LEMO Outdoor Microphone for Community and Airport Noise (0 V pol.)

Standard: IEC 61672-1
Configurable for 90 or 0 degrees of incidence
IP55 proof

GRAS 41AC-4 LEMO Outdoor Microphone for Community and Airport Noise (0 V pol.)

The 41AC-4 is an outdoor microphone for unattended use for a prolonged period of time. It can be used for community noise applications or for monitoring of overhead aircraft noise...

GRAS 41AM Permanent Outdoor Microphone System for airport noise

Dyn range: 20 dB(A) to 156 dB
Sensitivity: 50 mV/Pa
0° incidence (airport noise)

GRAS 41AM Permanent Outdoor Microphone System for airport noise

The GRAS 41AM Outdoor Microphone System is for outdoor use whenever trouble-free acoustic measurements and, in particular, noise monitoring around airports are required...

GRAS 41CN Permanent Outdoor Microphone System for community noise

Dyn response: 20 to 156
Sensitivity: 50 mV/Pa
90° incidence (community noise)

GRAS 41CN Permanent Outdoor Microphone System for community noise

GRAS 41CN Permanent Outdoor Microphone System for community noise..