BVRAMB Ambient Noise Microphone
Installation Instructions
BVRAMB issue 4
1
C O M M U N I C A T I O N S
1 Technical Description
1.1 I
NTRODUCTION
The BVRAMB Ambient Noise Sensing Microphone monitors the
ambient noise in a given area that enables the Public Address /
Voice Alarm system to change the volume to maintain
intelligibility.
The BVRAMB uses a Dynamic Microphone capsule, the output of
which is amplified and converted to produce a variable current
output. The amplifier used to convert the signal has band pass
filtering that ensures the system only responds to ambient noise
that affects the intelligibility of announcements.
An on-board Surveillance Tone Generator permanently monitors
the microphone capsule. A system fault will be announced should
the microphone capsule or on board amplifier fail.
The BVRAMB includes an option to allow one of three response
speeds to be selected.
If the Slow response is selected the system will only respond to an
average change of Ambient Noise.
If Fast is selected the system will react to short duration changes
in Ambient Noise.
Medium response is suitable for most installations.
