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NEW from GRAS:  low-noise microphone set (BNC)

exhibition:  What On Earth Colloquium, New Zealand

NEW from GRAS:  high resolution ear simulator

exhibition:  RotorTech 2018, Gold Coast

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The pre-polarised low noise microphone set you have been waiting for!


Low noise emission is increasingly important for all kinds of machines, equipment and consumer products, with quiet products are often preferred over more noisy ones. It therefore becomes increasingly important to measure close to the threshold of human hearing are needed.

A standard ½” microphone with high sensitivity (50 mV) has a noise floor about 16 dB(A), and the useful measurement range therefore begins at about 19 dB(A). To measure below this level, a special low-noise system is needed.

The 47HC is a prepolarized low-noise microphone set which builds on GRAS' 20+ years' of experience with state of the art low-noise measurement microphone systems. With this set, the performance previously reserved for externally polarized setups is now available for CCP (constant current powered) systems.

With a sensitivity of 450 mV/pa and a noise floor at 6.5 dB(A) or lower, it opens up for measurement levels down to about 10 dB(A). Its upper dynamic limit is 100 dB.

The microphone set has the same form factor as standard GRAS ½” microphone sets, and therefore it can be used with standard mounting accessories.


Click here for more details about the new Type 47HC microphone set.

Come and talk to us at the "What On Earth Colloquium, New Zealand

New Zealand's premier meeting of the Earth Observation community - 6+7 March 2018


There are huge potential economic and environmental gains to be made from applications and tools produced using Earth observation satellite data.  At this exciting time in the development of the NZ Space sector, this colloquium will:


We will be presenting information on Earth Observation solutions from Zodiac Data Systems


Click here for more details about the "What On Earth Colloquium".

NEW from GRAS - High Resolution Ear Simulator

New Ear Simulator - letting you work to 20 kHz with improved reliability and reproducibility


The GRAS RA0401 is a high resolution version of the well-known standardized 60318-4 ear simulator, the preferred tool for measurements with simulation of the acoustic load presented by the human ear.


Below 10 kHz, the standardized ear simulator does a good job at this. However, above 10 kHz its performance starts rapidly to deteriorate. The primary reason for this is its high Q resonance at 13.5 kHz.


The new GRAS High Resolution Ear Simulator mitigates this limitation. The steep resonance at 13.5 kHz has been replaced by a much dampened resonance and the useful frequency range is now extended to 20 kHz within a narrow tolerance band.


It complies with IEC60318-4 and its acoustic transfer impedance is within the tolerance band specified by IEC60318-4. From 10 to 20 kHz the transfer impedance is within ± 2.2 dB, resulting in much improved repeatability.


The High Resolution Ear Simulator is available in Externally Polarised (RA0401) or Pre-Polarised (RA0402) versions.


Click here for more details about the GRAS High Resolution Ear Simulator.

Come and talk to us at AEA RotorTech 2018, 24-26 May 2018

See us at the RotorTech 2018!


ETMC Technologies is proud to be exhibiting at RotorTech 2018 on the Sunshine Coast, Australia.  This Meeting will be held at the The Novotel Twin Waters Resort (270 Ocean Dr, Twin Waters QLD 4564, Australia)  on the 24th through 26th May 2018.


We will be showing equipment such CVR/FDR, Air Data Computers and other gear from Curtiss-Wright DS.


Come and say hi to us or 'talk shop' about your crash recorder and other avionics needs.


We look forward to seeing you there!


Click here for more details about RotorTech 2018

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