4
LI0151 – 4 July 2017
Introduction
The G.R.A.S. 41AC-2 LEMO Outdoor Microphone with RemoteCheck 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.
With the proper correction data, it can be used for 0 degrees of incidence, typically noise from
overhead aircraft. A USB flash drive with correction data is part of the delivery.
It is waterproof, rated at IP-55, and can operate unattended over a wide range of weather condi-
tions and temperatures for a very long period, i.e. a year or longer.
It uses a G.R.A.S. 40AF-S2 1/2” Externally Polarized Free-field Microphone, High Sensitivity and
a G.R.A.S. 26AJ 1/2’’ RemoteCheck Preamplifier with Integrated Connector.
Important.
The 40AF-S2 microphone and its protective grid have been modified for the 41AC-2.
Therefore, microphone and grid cannot be replaced by standard items.
Delivered Items
1/2" Ext. Polarized Free-Field Microphone, High Sensitivity
40AF-S2
1/2’’ RemoteCheck Preamplifier with integrated connector
26AJ
O-ring for preamplifier
OR2038
USB flash drive with correction data for 0° (resolution: 1/12 octave)
Wind Screen
AM0378
Release Tube (for LEMO connector)
GR1794
Top cone
-
Upper housing
-
Lower housing
-
1” pole mount adapter
RA0286
Tripod Adapter
GR1096
Tripod thread adapter
SK0017
