GRAS 40EU - GRAS Sound and Vibration

GRAS 40EU
1" Ext. Polarized Reference Pressure
Microphone
Freq range: 2.6 Hz to 8 kHz
Dyn range: 9.6 dBA to 146 dB
Sensitivity: 50 mV/Pa
GRAS Sound & Vibration A/S
Skovlytoften 33, 2840 Holte, Denmark
www.gras.dk
The 40EU is an IEC 61094 LS1P 1” externally polarized
pressure microphone that is rear-vented. It is a 1”
pressure microphone that is ideal for measurements in
couplers used for testing earphones. When flushmounted, it can measure sound pressures at
boundaries. It is highly suited as a laboratory-standard
microphone.
Technology
Introduction
The 40EU is an IEC 61094 LS1P 1" externally polarized
pressure microphone that is rear-vented.
It is a 1" pressure microphone that is ideal for
measurements in couplers used for testing earphones.
When flush-mounted, it can measure sound pressures at
boundaries. It is highly suited as a laboratory-standard
microphone.
40EU is individually factory-calibrated and delivered with
a calibration chart stating its specific open-circuit
sensitivity and pressure frequency response.
Typical applications and use
40EU can be used in precision reciprocity calibrations
because it is a linear reversible transducer. This means
that the electrical energy emitted by the 40EU is strictly
or linearly proportional to the acoustical energy it receives.
This is exactly what is required for such calibrations. When
carefully handled, the 40EU can retain its calibrated
properties for many centuries.
The 40EU is also highly suited as a laboratory reference
for secondary calibration of working-standard
microphones.
Compatibility
The 40EU requires a standardized ½" LEMO preamplifier
and an input module that supports this technology with a
7-pin LEMO connector.
System verification
For daily verification and check of your measurement
setup, we recommend using a calibrator like GRAS Sound
Level Calibrator 42AG
For proper sensitivity calibration, we recommend using a
pistonphone like GRAS Intelligent Pistonphone 42AP.
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
Date 01-04-2018.
GRAS 40EU 1" Ext. Polarized Reference
Pressure Microphone
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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
Technology
quality assurance department because you don't have to
worry about new serial numbers, etc.
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GRAS 40EU 1" Ext. Polarized Reference
Pressure Microphone
Page: 3
Specifications
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GRAS 40EU 1" Ext. Polarized Reference
Pressure Microphone
Frequency range (±2 dB)
Hz
2.6 to 8 k
Dynamic range lower limit (microphone thermal noise)
dB(A)
9.6
Dynamic range lower limit with GRAS preamplifier
dB(A)
14
Dynamic range upper limit
dB
146
Dynamic range upper limit with GRAS preamplifier @ +28 V / ±14 V
power supply
dB
142
Dynamic range upper limit with GRAS preamplifier @ +120 V / ±60 V
power supply
dB
146
Open-circuit sensitivity @ 250 Hz (±1 dB)
mV/Pa
50
Open-circuit sensitivity @ 250 Hz (±1 dB)
dB re 1V/Pa
-26
Resonance frequency
kHz
8
Microphone cartridge capacitance, typ.
pF
56
Microphone venting
Rear
IEC 61094-4 Compliance
LS1P
Temperature range, operation
°C / °F
-40 to 150 / -40 to 302
Temperature range, storage
°C / °F
-40 to 85 / -40 to 185
dB/°C / dB/°F
-0.01 / -0.006
dB/kPa
-0.0016
% RH
0 to 100
dB/% RH
-0.0013
dB re 20 µPa
67
Temperature coefficient @250 Hz
Static pressure coefficient @250 Hz
Humidity range non condensing
Humidity coefficient @250 Hz
Influence of axial vibration @1 m/s²
CE/RoHS compliant/WEEE registered
Weight
Date 01-04-2018.
Yes / Yes, Yes
g / oz
32 / 1.129
Specifications
GRAS 40EU 1" Ext. Polarized Reference
Pressure Microphone
Typical frequency response
GRAS Sound & Vibration reserves the right to change specification without notice.
Date 01-04-2018.
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Dimensions
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GRAS 40EU 1" Ext. Polarized Reference
Pressure Microphone
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Ordering Info
GRAS 40EU 1" Ext. Polarized Reference
Pressure Microphone
Optional items
GRAS RA0073
Adapter for 1” Microphone and ½” Preamplifier
GRAS RA0017
Adapter for 1” Microphone and ½” Preamplifier
GRAS CA0001
Traceable Calibration of Microphone
GRAS CA2001
Accredited Calibration of Microphone
GRAS Sound & Vibration reserves the right to change accessories without notice.
Date 01-04-2018.
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We Make Microphones
Tradition
Innovation
Quality
Since the establishment in 1994,
GRAS has been 100% dedicated to
developing and manufacturing
high-quality measurement
microphones and related acoustic
equipment.
We work with everybody with an
interest in sound or noise within
the fields of aerospace,
automotive, audiology, consumer
electronics, noise monitoring,
building acoustics and
telecommunications.
At GRAS we know that in order for
you to trust your measurement
results; signal quality, stability and
robustness are essentials. We
design and build them to perform
under real life conditions – and
beyond.
GRAS Sound & Vibration A/S
Skovlytoften 33, 2840 Holte, Denmark
www.gras.dk