Related Manuals for G.R.A.S. 41AC-3
Summary of Contents for G.R.A.S. 41AC-3
- Page 1 Instruction Manual G.R.A.S 41AC-3 CCP Outdoor Microphone with RemoteCheck for Community & Airport Noise www.gras.dk LI0152– 4 July 2017...
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Page 2: Revision History
Revision History Any feedback or questions about this document are welcome at gras@gras.dk. Revision Date Description 26 August 2014 First edition 4 July 2017 42AG substituted for the obsolete 42AB Copyright Notice © 2014, 2017 G.R.A.S. Sound & Vibration A/S http://www.gras.dk Any technical documentation that is made available by G.R.A.S. -
Page 3: Table Of Contents
Contents Introduction .................. 4 Delivered Items ................4 Installation .................. 6 System Integration ..............12 Accessories ................14 Specifications ................14 Calibration, Warranty and Service ........... 18 LI0152 – 4 July 2017... -
Page 4: Introduction
Introduction The G.R.A.S. 41AC-3 CCP Outdoor Microphone for Community & Airport Noise is a precision microphone set (IEC 61672-1) for monitoring community noise and the noise of overhead aircraft. It can be used for monitoring of noise with 90 degrees of incidence, typically community noise. - Page 5 41AC-3 is delivered preassembled except for the windscreen and thread adapter. ½" microphone 40AE-S2 Lower housing Upper housing Windscreen AM0378 O-ring OR2038 Preamplfier 26CA 2-piece 1” pole mount Top cone adapter RA0286 Tripod and thread adapter SK0017 Fig. 1. The parts of 42AC-3.
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Page 6: Installation
The 41AC-3 is designed for permanent installation and therefore comes with an adapter for mounting on a 1” pole. See Fig. 2 and Fig. 3, 3. The 41AC-3 ’s housing is attached to the mounting fittings with a M18 x 1.5 thread. - Page 7 Removing the Preamplifier As delivered, the microphone set is mounted inside the housing. To attach the cable, you must remove the top, remove the microphone and pull out the preamplifier. 1. Unscrew the top cone from the housing. 2. Set it aside and ensure that it is protected from dirt and moisture. 3.
- Page 8 Connecting the Cable to the Preamplifier and Remounting the Microphone Set 1. Connect the cable to the preamplifier. 2. Push the preamplifier up through the lower and upper housing. 3. To expose the thread for the microphone, ensure that the preamplifier is pushed up as far as it will go.
- Page 9 Mounting the Top Cone When the microphone has been mounted on the preamplifier, you can mount the top cone. 1. Screw on the top cone. 2. Ensure that the top cone is properly fastened. Fig. 5. Mounting the upper housing and the top cone. LI0152 –...
- Page 10 Mounting the Windscreen The windscreen is glued onto a plastic tube that ensures that it can be positioned correctly: • When pushed down, the windscreen tube is prevented from going too far by the upper hous- ing’s conical shape. • When the windscreen is pushed as far down as it will go, it will be kept in place by a locking groove.
- Page 11 Disassembly You can disassemble the 41AC-3 by reversing the procedure described on the preceding pages. The windscreen tube is held in place by a locking mechanism. Therefore, some force must be applied to slide the tube back up. 1. Push at the end of the windscreen tube with a finger nail or a piece of hard plastic.
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Page 12: System Integration
The correction data contained on the USB flash drive that is part of the delivery must be used if the 41AC-3 is used for 0 degrees of incidence. The correction data are measured with a resolu- tion of 1/12 octave. -
Page 13: Accessories
Accessories Intelligent Pistonphone 42AP Pistonphone 42AA Multifunction Sound Calibrator 42AG 3 m BNC - BNC Cable AA0035 10 m BNC - BNC Cable AA0037 30 m BNC - BNC Cable AA0038 Customized length BNC - BNC Cable AA0039-CLXXXX Specifications Dynamic range lower limit (microphone thermal noise) 17 dB(A) Dynamic range upper limit 138 dB... - Page 14 Frequency Response and Directional Response 41AC Typical Frequency Response Typical frequecy responce 90° incidence 90° incidence 0° incidence 0° incidence 0° incidence with corr. 0° incidence with correction IEC 61672-1 tolerance + IEC expanded lim+ IEC expanded lim- IEC 61672-1 tolerance - IEC lim + IEC 61672-1 accept.
- Page 15 Acceptance limits for deviations of directional response ±90° Directional Response Measurements 41AC w. windscreen 0° and 90° Incidence 0º incidence Lim dev ±90º 0° incidence 0° incidence 90° incidence 90° incidence Lim w. uncertanty ±90º IEC 61672-1 tolerance Lim dev ±90º IEC 61672-1 acccep.
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Page 16: Calibration, Warranty And Service
Warranty All G.R.A.S. products are made of high-quality materials that will ensure life-long stability and robustness. The 41AC-3 is delivered with a 5-year warranty. The windscreen comes with a 6-month warranty, this warranty covers defective workmanship only and not the effects of normal use.