Portfolio Description
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  • March 14, 2017


G.R.A.S. is an ISO 9001:2008 certified company in the field of high-quality measurement microphones and related acoustic equipment. Found in 1996 by Gunnar Rasmussen, G.R.A.S. is a family owned business focused on providing only the best quality and most precise microphones and acoustic calibration equipment for their customers measurement needs.
G.R.A.S. aims to offer the most advance and durable microphone solutions in the industry. For assured quality, G.R.A.S. products go through a series of “Highly Accelerated Life Tests” (HALT Testing) that test simulate day to day handling and real life situations. It includes impact, vibration, humidity and temperature stress tests to ensure product reliability, stability and robustness when in use.

G.R.A.S. Measurement Microphone Sets

G.R.A.S measurement microphones can be applied in many fields for sound and noise testing. They have been used in many fields include aerospace, automotive, consumer electronics, noise monitoring, building acoustics, telecommunications, education, audiology and many more. G.R.A.S. microphones come in Constant Current Supply (CCS) and Traditional Power (LEMO) and cover a wide frequency range, dynamic range and application situations for the users needs. Microphones can be further specialized and customized via G.R.A.S. measurement microphone cartridges to meet the users specific needs.

To find out more about how G.R.A.S. microphones can be applied for your testing and measurement means, contact TME Systems today.

Ultra-Thin Precision Microphones

The World´s Thinnest Condenser Microphones

The GRAS Ultra-Thin Precision (UTP) Microphones provide the ability to understand boundary layer and turbulence noise on different vehicles. The UTP microphones disrupt today’s manufacturing practices and are based on patented technology.

UTP microphones combine the high precision and reliability of GRAS measurement microphones with the need for extremely low-profiled (less than 1 mm) microphones with minimum turbulence influence. With their unique form factor and easy mounting, UTP microphones are specifically designed for in-situ boundary layer testing, when neutral impact and high precision is important. Together with our range of Surface and Flush microphones, UTP microphones cover all boundary layer testing applications in the automotive, aerospace and other industries.

Find out more about the GRAS Ultra-Thin Precision (UTP) Microphones

Special Microphones and Hemispheres

G.R.A.S. special microphone sets are specially designed for various situations, conditions and methods of testing. Build with the same high quality and precision, these reference microphones can be applied to an array of measurements including pressure, intensity, environment, surface noise, low noise, Infra-sound and aeroacoustic testing.
G.R.A.S. hemispheres allow sound power measurements on everything from small sized personal electrics to office machines and IT products, household appliances, power tools and smaller engines. Coming in both 1 and 2 meters diameter, they offer a high degree of freedom of location and are ISO 3744, 3745 and 3746 (ANSI S12.54, S12.55, S12.56) compliant.

Ear Simulator Microphones

The G.R.A.S. line of Artificial Ears are complete test jig for acoustically testing both concha and insert types earphones coupled to the ear via inserts such as tubes and ear moulds. They can also be used for headphone and headset testing, both circumaural and supra-aural types, all common types of hearing-aids, telephone handsets and other ear related equipment.

Artificial ears can do numerous test and they can be performed according to the following standards:

  • IEC 60959
  • IEC 60318-4: Occluded-ear simulator for the measurement of earphones coupled to the ear by ear inserts.
  • ITU-T Recommendations P.57 (08/96) Series P: Telephone transmission quality, Objective measuring apparatus: Artificial ears/Pinna simulator

Microphone Calibration

G.R.A.S. microphones are calibrated and verified according to international standards, and the calibration data are included with the products. Despite sturdy construction, calibration at regular intervals is still the way to safeguard the quality of your measurements and to eliminate the possible “costs” caused by inaccurate equipment.
TME Systems is the G.R.A.S. Microphone Calibration Center in Singapore and South East Asia providing calibration to ISO 17025 standard. Certificated are accredited by DANAK, the Danish Accreditation Fund and traceable to the National Physical Laboratory (NPL) in England.
TME Systems can provide calibration for almost all G.R.A.S. microphone models and most leading measurement microphone makers in the world. Contact TME Systems for a quote today!

Find out more on G.R.A.S. Microphone Callibration

Accreditation from G.R.A.S.


We are pleased to announce our authorization by G.R.A.S. Sound & Vibration, Denmark, to calibration G.R.A.S. Microphone, G.R.A.S. Microphone Sets and G.R.A.S. Preamplifiers.

Leave a note an we will get back to you in 2 working days.

For more Standard, Special and Customized Microphone Solutions, contact TME Systems today.