G.R.A.S. Measurement Microphones and Acoustic Equipment

G.R.A.S. develops and manufactures high-quality measurement microphones and related acoustic equipment.

Noise measurement microphones for aerospace applications

All industry sectors bring their own challenges but aerospace testing is one that pushes microphones to their limits. Measurements often need to be done in high speed, turbulent air flows where it is important that the microphone doesn’t affect the measurements.

We work with anybody 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.

Measurement microphones for aeroacoustic testing

G.R.A.S. has been a leader in the aeroacoustic field for many years and has specially designed many microphones to overcome the key challenges faced by aerospace engineers.

Our microphone range includes a wide selection of externally and pre-polarised, free-field and random incidence microphones for applications in various pressures. The company also offers preamplifiers, hemispheres and low noise measurement systems, as well as:

• Turbulence screens
• Microphones; surface, flush mount, intensity, outdoor and environmental, probe, plate, and QC
• Ear and mouth and head and torso simulators
• Electrostatic actuators

Measurement microphone design and testing

G.R.A.S. performs stringent testing on its measurement microphones to ensure high-reliability.

Using a series of highly accelerated life tests (HALT), 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 operation in real-life situations, to ensure consistently optimal measurements.

All our microphones are produced in high-quality stainless-steel and we can confidently give a five-year warranty. The comapny also repairs any accidental damage.

Company history

Since 1994, G.R.A.S. has focused on the development and manufacture of high-quality measurement microphones and related acoustic equipment. The company was founded by the renowned Danish acoustics pioneer Gunnar Rasmussen, who has contributed to the world of sound and vibration with his unique ideas and designs for more than six decades.

From the first reproducible 1in condenser measurement microphone that enabled quality measurements and instrumentation for acoustic calibration, Rasmussen’s ingenuity and foresight led to the popular acoustic sensor: the 1/2in measurement microphone. The 1/4in and 1/8in microphones followed with 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 1in pressure microphone design.