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LI0063 – Revision 29 May 2015
Introduction
The Scope of this Manual
This manual describes how to mount the G.R.A.S 1/2”, 1/4” and 1/8” flush-mount microphone
sets, how to connect them, and how to perform sensitivity and frequency calibration.
Two mounting options are described:
•
Mounting with Adapter
An adapter for each microphone size is available. The adapters are made from a non-
conductive plastic material that provides electrical insulation between microphone and test
object. The microphone set is attached to the adapter with an O-ring. This makes installation
and removal of the microphone set easy.
•
Direct Mounting
The measures you need to make your own mounting solution are provided, without the use of
a G.R.A.S. mounting adapter.
Brief Description
Venting
The microphone is front-vented for air pressure equalization. This is realized through a tiny
hole that is visible when the microphone grid is removed. It is important that the venting is not
blocked.
TEDS
The G.R.A.S. flush-mount microphones have TEDS according to IEEE 1451.4, 27 v 1.0. The
TEDS (Transducer Electronic Data Sheet) is a memory in the microphone. At delivery, the factory
has stored the G.R.A.S. type number, serial number and the sensitivity value as measured during
factory calibration.
If your measurement platform supports intelligent transducers according to IEEE 1451.4 (TEDS),
this information will automatically be retrieved. G.R.A.S. updates the stored sensitivity value as
normal procedure in the calibration service.
