Bộ micro gắn phẳng GRAS 47AX 1/2'' CCP

Technology

Typical applications and use

Flush mounting in confined spaces
Flush mounting in clay models
Ground array measurements
General noise measurements

Design

With a height (to the diaphragm) of only 8 mm, 47AX is suitably designed for flush mounting in plates in ground array applications and other applications with size constraints.

The microphone is a prepolarized pressure microphone with a dynamic range from 22 dB to 146 dB and a frequency range from 3.15 Hz to 20 kHz. The built-in preamplifier is a low noise constant current power (CCP) type, with a built-in TEDS circuit for automatic transducer identification. The set has an integrated 1.5 m cable with Microdot connector plus an adapter for BNC cable.

Flush-mounting is ideal where holes can be made in the structure, such as a clay model, to accommodate the front-vented 47AX. A rear-vented version is also available, the 47AX–S1.

It is included with the GRAS 67AX Ground Array Set, which has a 400 mm diameter mounting plate.

The 47AX is based on the IEC 61094 standard for measurement microphones.

Calibration

When leaving the factory, all GRAS microphones have been calibrated in a controlled laboratory environment using traceable calibration equipment. Depending on the use, measurement environment and internal quality control programs we recommend that the microphone is recalibrated at least once a year.

We offer two kinds of calibration as an optional after-sales service: GRAS Traceable Calibration and GRAS Accredited Calibration.

GRAS Traceable Calibration is a traceable calibration performed by trained personnel under controlled conditions according to established procedures and standards. This is identical to the rigorous calibration that all GRAS microphones are subjected to as an integral part of our quality assurance.

GRAS Accredited Calibration is performed by the GRAS Accredited Calibration Laboratory that has been accredited in accordance with ISO 17025 by DANAK, the Danish Accreditation Fund.

If you want a new microphone set delivered with an accredited calibration in stead of the default factory calibration, specify this when ordering.

Learn more at gras/calib.

Quality and warranty

GRAS microphone sets are made of components from our proven standard portfolio and are all manufactured of high-quality material and branded parts that were chosen and processed to ensure life-long stability and robustness.

All parts are manufactured and assembled at the factory in Denmark by skilled and dedicated operators in a verified clean-room environment. The microphone diaphragm, body and unique protection grid are made of high-grade stainless steel and make the microphone set resistant to physical damage as well as corrosion caused by aggressive air or gasses.

This, together with the enforced gold-plated microphone terminal guarantees a highly reliable connection. Thanks to the high quality, our warranty against defective materials and workmanship is 5 years.

Service

Should you by mistake damage the diaphragm on a GRAS microphone we will in most cases be able to exchange it at a very reasonable cost and short turn-around time. This not only protects your investment but also meets your quality assurance department since you do not have to worry about new serial numbers etc.

Specifications

Parameter	Unit	Value
Polarization/Connection	–	0 V / CCP
Frequency range (±1 dB)	Hz	5 to 12.5 kHz
Frequency range (±2 dB)	Hz	3.15 to 20 kHz
Dynamic range lower limit with GRAS preamplifier	dB(A)	22
Dynamic range upper limit with GRAS CCP preamplifier	dB	150
Sensitivity @ 250 Hz (±2 dB)	mV/Pa	12.5
Power supply (Constant Current Power)	mA	2 to 10
Microphone venting	–	Front
IEC 61094-4 Designation	–	WS3P
Output impedance	Ω	< 50
Temperature range, operation	°C / °F	-30 to 70 / -22 to 158
Temperature range, storage	°C / °F	-40 to 85 / -40 to 185
Temperature coefficient @250 Hz	dB/°C	-0.01
Static pressure coefficient @250 Hz	dB/kPa	-0.008
Humidity range non-condensing	% RH	0 to 90
Humidity coefficient @250 Hz	dB/% RH	< 0.001
Influence of axial vibration @1 m/s²	dB re 20 µPa	66
TEDS (IEEE 1451.4)	–	27 v.1.0
Connector type	–	Microdot 10/32
CE/RoHS compliant / WEEE registered	–	Yes / Yes / Yes
Weight	g / oz	9 / 0.317