GRAS 48LX-4 UTP Line-Array, 4 Channel, Medium Pressure

Introduction

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.
• Wind-tunnel testing.

Field Verification

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.

Calibration

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.

Service

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.