Since the establishment in 1994, G.R.A.S. have been 100% dedicated to developing and manufacturing high-quality measurement microphones and related acoustic equipment.
Since the establishment in 1994, G.R.A.S. have been 100% dedicated to developing and manufacturing high-quality measurement microphones and related acoustic equipment. We are founded by the Danish acoustics pioneer Gunnar Rasmussen who for more than 60 years has contributed to the world of sound and vibration with his unique ideas and designs. From the first reproducible 1” condenser measurement microphone that enabled quality measurements and instrumentation for acoustic calibration, Mr. Rasmussen’s ingenuity and foresight led to the world’s most popular acoustic sensor: The 1/2” measurement microphone. Then the 1/4” and 1/8” microphones followed with outstanding dynamic and high-frequency capability that brought higher definition and transparency into impulse noise diagnostics. Many variants have been made available over the years; all based on Gunnar Rasmussen’s original 1” pressure microphone design.
When celebrating our 20 years' anniversary in 2014 we documented the story of our founder, Gunnar Rasmussen. Order your copy of the G.R.A.S. jubilee book.
At G.R.A.S., we and our customers benefit daily from Mr. Rasmussen’s exceptional understanding of acoustics, physics, electronics and measurement needs. Not only in R&D but throughout the organisation, we are proud to develop, produce and offer the world's best measurement microphones and accessories. And as a family company, now owned and led by the two sons, Per Rasmussen and Peter Wulf-Andersen, we safeguard our heritage and knowledge to help create new opportunities with our customers. We work with everybody with an interest in sound or noise within the fields of aerospace, automotive, audiology, consumer electronics, noise monitoring, building acoustics and telecommunications, metrology, education, consultancy, legislation and system integration.
When our R&D team develops a measurement microphone, it must undergo the most demanding tests to prove that it deserves to bear the G.R.A.S. name. Using a series of “Highly Accelerated Life Tests” we ensure that our microphones live up to the high quality and precision that our customers have come to expect and trust. Our HALT tests actively accelerate the lifetime of a microphone by simulating the handling and use it is exposed to in real life situations.
We bake it, we humidify it, we shake it and we even try to break it, just to make sure that you get the very best measurement results every time. Learn more about our microphone HALT testing here.
All our microphones are solely produced in stainless steel and in a quality that allows for a 5 year warranty. Should you by mistake damage the diaphragm on a G.R.A.S. microphone, our special technique enables repair at very reasonable price.
G.R.A.S. is ISO 9001:2008 certified.
Sound Power Testing - Sound Power made easy 声功率测试- 轻松量度声功率 GRAS 半球型传声器保持架The hemispheres will hold and position the measurement microphones according to the standards and have been designed with focus on your workflow. 半球型传声器保持架将根据测试标准来保持以及定位麦克风测量位置，并专注于您的工作流程。 -------------------------- More Details: G.R.A.S hemispheres
The G.R.A.S. 67TS-1-CL Turbulence Screen Kit (67TS-1-CL 湍流屏幕) GRAS is designed for aeroacoustic testing in solid-walled wind tunnels. 专为实心壁风洞中的空气声学测试而设计。 s&v More Details: G.R.A.S Turbulence Screen Brochure
The 42AC is an extremely stable laboratory standard sound source which can also be used for field calibrations – it retains its high accuracy even under hostile environmental conditions. 42AC是一种非常稳定的实验室标准声源，也可用于现场校准 - 即使在恶劣的环境条件下也能保持高精度。
The GRAS 43AG Ear and Cheek Simulator is a unique, multi-faceted and multi-purpose tool that helps you accomplish the job in an effective and efficient manner. We call it the table-top KEMAR as it offers you much of the KEMAR capability in a convenient and portable packaging. GRAS GRAS 43AG 耳廓及面颊模拟器是一款独特、多面、多用途的工具，可帮助您以有效和高效的方式完成工作。...
KB5000 is a right pinna with anthropometric concha and ear canal for KEMAR. It is made of soft silicone, 35 Shore OO hardness. GRAS KB5000是用于KEMAR的一款带有人体测量的仿真外耳和仿真耳道的右边仿真耳廓。 它由柔软的硅树脂制成，属于35 Shore OO硬度类別。
Nosecones 鼻锥 Proper use of a microphone with a nosecone is to aim the nosecone towards the air flow. The nosecone has an inner threading and is installed by replacing the protection grid with the nosecone. 正确使用带有鼻锥的麦克风是将鼻锥对准空气流动。鼻锥具有内螺纹，是通过替换保护网格以安装鼻锥。 G.R.A.S More Details: Nosecone
Typical applications and use 典型应用和使用 - Very Low Sound pressure measurements 极低的声压测量- Lownoise product measurements 低噪音产品测量- Lowlevel Sound power measurements 低水平声功率测量- Measurements on hard-disk drives, computer products, quiet rooms etc. 硬盘驱动器、计算机产品、安静房间等的测量 G.R.A.S.
The GRAS 47AC is a 1/2" CCP precision condenser microphone set for infra-sound measurements in open acoustic fields. G.RAS 47AC是1/2寸 CCP精度电容式传声器，例如，开放的声场红外声音测量设置。
The GRAS 42AG Multifunction Sound Calibrator is a portable, battery operated sound source for calibration and check of microphones and sound level meters. It is designed for field use and comes with a protective casing. It conforms to the requirements in IEC 60942 for a class 1 sound calibrator. GRAS 42AG多功能声音校准器是一种便携式电池供电声源，用于校准和检查麦克风和声级计。...