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 

• Array microphones
• Flush-mount microphones
• Infra-Sound Microphones
• Intensity Microphones
• Intensity Probes
• Lownoise measuring systems
• Plate microphone kits
• Probe microphones
• QC microphones
• Surface microphones
• Turbulence Screen Microphones