GRAS 48LX-4 UTP Line-Array, 4 Channel, Medium Pressure
Acoustic measurements in laminar and turbulent airflow require low-profile microphones to avoid disturbing the sound field.
This is why we at GRAS have developed the UTP microphones – Ultra Thin Precision microphones. They combine the advantages of the classical measurement microphone – wide frequency range, accuracy, and repeatability – with an ultra-small form factor.
The GRAS 48LX-4 is a line array with four UTP microphones. It is only 1.35 mm in height, and therefore it is ideal for measurements in boundary layers and turbulence.
Explore the Benefits
The very small things which make the BIG difference
UTP provides accurate data from precision measurement microphones manufactured to narrow specifications.
With a height of 1.35 mm the door to a whole new world of what can be measured in boundary layers and turbulent flow opens.
The line array configuration provides easy connection and avoids acoustic interference from messy cabling.
Easy Mounting and In-situ Verification
As shown below, 48LX-4 is easily mounted using masking tape. Once mounted, the setup can quickly be verified in-situ, a major advantage when you want to check the integrity of your measurement setup.
Easy mounting, CCP interface with integral cabling and in-situ verification all add up to reduced setup time and faster measurements- with reliable data.
Rubber fairings with a rise angle of 6.5 degrees ensure minimal disturbance to the sound field/airflow.
Easy Mounting and In-Situ Verification
The UTP microphones are easy to mount and remove, even in confined spaces.
48LX-4 line-array is mounted using masking tape. Reproducing a previous setup can be done quickly, and geometry is maintained.
Fast and reliable in-situ verification saves time and increases confidence.
A special verification adapter with a soft cushion allows for quick, easy, and reliable in-situ verification. Four distance spacers ensure that the correct volume is achieved and that this volume can easily be reproduced.
Even on curved surfaces, this verification method is so precise that dismounting is not necessary.
Freq range: 20 Hz to 20 kHz (±1 dB)
10 Hz to 70 kHz (±3 dB)
Dyn range: 54 dB(A) to 170 dB
Sensitivity: 0.6 mV/Pa (±3 dB)
Use: For aeroacoustic measurements
48LX-4 is an Ultra-Thin Precision (UTP) surface microphone line-array for aeroacoustic testing.
It consists of 4 low-profile 1/4" CCP medium-pressure condenser microphones. They are mounted with rubber fairings in a line array configuration on a flexible PCB. The height is 1.35 mm and the angle of the fairings is 6.5 degrees.
It has TEDS for easy channel identification. The 4 channels are connected to a 15 pin D-Sub connector. The total cable length is 3 meters.
48LX-4 line-array is easy to mount and demount. The flexible PCB/plastic strip is about 10 mm wider than the microphones on each side. Therefore, the array can be mounted using masking tape straddling the top side of the strip and the structure.
Remounting is easy, and the geometry of the mounting can easily be maintained and used in a different location or measurement setup.
The strip can be bent along its length, making it possible to mount it on curved surfaces.
Typical applications and use
48LX-4 is for low to medium level surface pressure measurements on planar and curved surfaces for measurements in boundary layers and turbulence, for example in
Wind-induced noise measurement on vehicles.
For sensitivity verification in the field using a sound calibrator, a special adapter is available, the RA4800 Adapter for Sensitivity Verification of Flush/Surface Microphones. RA4800 is furnished with a round, soft pad similar to those used on over-the-ear headphones. This pad ensures a sealed cavity for the calibration signal. Read more here.
With this adapter, quick and convenient in-situ sensitivity verification is possible, and therefore it is possible to check the integrity of the measurement setup immediately before measurements.
For sensitivity and frequency calibration, The RA4803 Sensitivity and Frequency Calibration Kit for 48LX-4/48LX-8 is available.
This kit contains an adapter for sensitivity calibration with a pistonphone, and an electrostatic actuator for frequency calibration.
48LX-4 is checked and calibrated before leaving the factory. An individual calibration chart is supplied with each microphone and includes an individual pressure frequency response.
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, which 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 warranty period is 2 years.
The warranty covers defective materials, and workmanship for the sensor element, printed circuit board, and housing.
Cable and connectors are covered by a 6 months warranty period.
Should you by mistake damage or destroy a microphone element or the cable, we offer repair or exchange service of the whole line array.
GRAS Sound & Vibration continually strives to improve the quality of our products for our customers. Therefore, the specifications and accessories are subject to change.
|Sensitivity difference between microphones||dB||±1|
|Phase difference between microphones||degrees||±5|
|TEDS UDID (IEEE 1451.4) - one for each microphone||I27-0-0-0U|
|Connector to strip||15 pin D-Sub male|
|Dimensions single sensor, width x length||mm||9 x 18|
|Dimensions strip, width x length||mm||50 x 260|
|Weight||g / oz||20 / 0.71 (excl. cable)160 / 5.64 (incl. cable)|
The frequency response is within ±3 dB up to 70 kHz
|GRAS 48LX-4||UTP Microphone Line Array, 4 Channel, Medium Pressure, with cable|
|GRAS DB0507||Mounting Tape for 48LX Series Line Arrays|
|GRAS RA4800||Adapter for Sensitivity Verification of Flush/Surface Microphones|
|GRAS RA4803||Sensitivity and Frequency Calibration Kit for 48LX-4/48LX-8|
|GRAS AA4800-4||1.5 m 48LX-4 Splitter Cable D-Sub/4xBNC Male|
|GRAS AA4801-4||1.5 m 48LX-4 Splitter Cable D-Sub/4xMicrodot Male|
|GRAS AA4802-4||1.5 m 48LX-4 Splitter Cable D-Sub/4xSMB Female|
|GRAS AA4803-4||1.5 m 48LX-4 Splitter Cable D-Sub/4xInfiniteband|
|GRAS AA4804-4||1.5 m 48LX-4 Splitter Cable D-Sub/D-Sub 25|
|GRAS AA4810||5 m 48LX Extension Cable D-Sub/D-Sub|
|GRAS AA4811||10 m 48LX Extension Cable D-Sub/D-Sub|
|GRAS AA4812-CL||48LX Extension Cable D-Sub/D-Sub Custom Length|
|GRAS DB0507||Mounting Tape for 48LX Series Line Arrays|