GRAS 46BG 1/4" CCP Pressure Standard Microphone Set, High Pressure

Freq range: 3.15 Hz to 70 kHz
Dyn range: 60 dB(A) to 184 dB
Sensitivity: 0.25 mV/Pa

GRAS 46BG 1/4" CCP Pressure Standard Microphone Set, High Pressure

Technology

Introduction

Through a close cooperation with our customers, we know that data-safety is highly important because the costs related to unsuited and unreliable sensors may determine whether your project turns into a success or not.

For our users, data safety translates directly into requests for easier microphone selection, simple system configuration and reduction of measurement errors.

To meet these requirements, we invented the microphone set concept. It is simple, reliable and robust and consists of a microphone cartridge and preamplifier combination, which is calibrated as one unit. This eliminates errors because there is only one sensitivity value to account for and the risk of contaminating the interface is eliminated. Combine this with our unique and proven design and you have the most reliable measurement microphone sets available in the industry today.

Typical application and use

The 46BG is a pressure microphone set and as such optimized for acoustic measurements of the sound source in a closed coupler or the measurement of sound pressure at a boundary or wall; in which case the microphone forms part of the wall and measures the sound pressure on the wall itself.

Regarding temperature range, see the Specifications. Should higher temperature limits be required, we recommend considering  the GRAS probe microphones where the microphone and preamplifier can be isolated from the hot source.

Design

The GRAS 46BG is a high-performance standard microphone set. In our clean-room environment the set is assembled and sealed with a label. However, the microphone set can be dismounted, if you wish to use the components separately.

Microphone
The microphone cartridge is the high-quality IEC  61094 WS3P standardized GRAS 40BG 1/4" Prepolarized Pressure Microphone, designed for long-term reliability in multiple environments.

Preamplifier
The preamplifier is the GRAS 26CB Preamplifier which is inclusive TEDS and based on our well-known circuit board substrates. In the industry these are famous for their low self-noise, wide frequency and excellent slew rate performance.

Compatibility

To perform as specified the GRAS 46BG microphone set requires a constant current input module that can deliver 4 mA and 24 V unloaded CCP voltage supply. If the constant current supply is lower, the capability of driving long cables is reduced and consequently the upper frequency is reduced. If the voltage supply is lower it will influence the upper dynamic range.

The microphone set is terminated with a 10/32 Microdot female connector. Ready to use coax cable assemblies of various types and lengths are available in standard as well as customized lengths.

The 46BG is IEEE 1451.4 TEDS v. 1.0 compliant. If your measurement platform supports Transducer Electronic Data Sheets you will be able to read and write data like properties and calibration data.

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

All GRAS microphones are made of high-quality materials that will ensure life-long stability and robustness. The microphones are all assembled in verified clean-room environments by skilled and dedicated operators with many years of expertise in this field.

The microphone diaphragm, body, and improved protection grid are made of high-grade stainless steel, which makes the microphone resistant to physical damage, as well as corrosion caused by aggressive air or gasses.

This, combined with the reinforced gold-plated microphone terminal which guarantees a highly reliable connection, enables GRAS to offer 5 years warranty against defective materials and workmanship.

Service

If you accidentally damage the diaphragm on a GRAS microphone, we can — in most cases — replace it at a very reasonable cost and with a short turn-around time. This not only protects your investment, but also pleases your quality assurance department because you don’t have to worry about new serial numbers, etc.

Specifications

Frequency range (±2 dB)
Hz
3.15 to 70 k
Dynamic range lower limit with GRAS preamplifier
dB(A)
60
Dynamic range upper limit with GRAS CCP preamplifier
dB
184
Set sensitivity @ 250 Hz (±2 dB)
mV/Pa
0.25
Set sensitivity @ 250 Hz (±2 dB)
dB re 1V/Pa
- 72
Output impedance
Ω
<50
Output Voltage Swing, min. @ 24-28 V CCP voltage supply
Vp
8
Power supply min. to max.
mA
2 to 20
Power supply min. to max. (single/balanced)
V
N/A
DC bias voltage, typ.
V
12
Microphone venting
Rear
IEC 61094-4 Compliance
WS3P
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 / dB/°F
-0.01 / -0.006
Static pressure coefficient @250 Hz
dB/kPa
-0.01
Humidity range non condensing
% RH
0 to 95
Humidity coefficient @250 Hz
dB/% RH
0.001
Influence of axial vibration @1 m/s²
dB re 20 µPa
63
TEDS UTID (IEEE 1451.4)
27 v. 1.0
Connector type
Microdot 10/32
CE/RoHS compliant/WEEE registered
Yes/Yes/Yes
Weight
g / oz
8 / 0.282

 

Typical pressure frequency response of the 46BG


GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

Dimensions

Ordering info

Optional items

GRAS AA0070

3 m Microdot - BNC Cable

GRAS AA0073-CL

Customized Length Microdot - BNC Cable

GRAS AA0087-CL

Customized Length Microdot - Microdot Cable

GRAS AL0029

1/4" Microphone Holder, POM

GRAS AL0013

1/4" Microphone Holder, Stainless Steel

GRAS AL0005

Swivel head

GRAS AL0006

Tripod

GRAS RA0022

1/4" Nosecone

GRAS AM0071

Windscreen for 1/4" Microphones

GRAS RA0127

Rain-protection cap for 1/4” microphones

GRAS 12AL

1-Channel CCP Power Module with A-weighting filter

GRAS 12AQ

2-Channel Universal Power Module with signal conditioning and PC interface

GRAS 42AG

Multifunction Sound Calibrator, Class 1

GRAS 42AP

Intelligent Pistonphone, Class 0

GRAS CA0029

Traceable Calibration of Microphone Set

GRAS CA2301

Accredited Calibration of Microphone Set

GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

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