BRUEL & KJAER 2619 User Manual

2.7 NOISE
The self generated noise spectrum is shown in F ig.2. 7 as a 1/3 octave
analysis from
20 Hz to 40 kHz. Total noise in the wide band appears at the
right hand end of the scale, shown weighted wit,", A, B, C networks, and
with a linear response
20 Hz-40 kHz.
2.8 TEMPERATURE ENVIRONMENT
The preamplifier operates satisfactorily in the temperature range -20 to
+ 60
0
C. With extension UA 0196 it is possible to keep the preamplifier in a
cooler
environment than the microphone, which can operate in tempera -
tures of 150
0
C.
A heater coil is built into the microphone end of the preamplifier and
prevents condensation in high humidity environments . This i~ automatically
connected to the heater supply in ordinary B&K microphone input sockets.
If, however, the microphones are used for extremely accurate measurements
and calibration or under circumstances where the temperature rise may
cause problems, e.g. in contact with human skin, it is recommended that the
heater be disconnected, or the goose-neck extension be used. Similar precau-
tions must be taken when used in high temperature environments, over
60
0
C. When used in a battery driven set-up the heater should normally be
disconnected.
l·'O ~ J . ,OOOOODOOODOO OOD O DDOOOOOOO OO OO OOO OO OOD OOOOOO
000
' • • 11O(~'''' -. ... _ ....
2619
,
: ,~ ~ ~
: ;; 1';;;" '-
~ KJO ~ i oo
~ , .. r~~
-1",,/
Fig . 2. 7. Noise spectrum. 1/3 octave analysis.
11

BRUEL & KJAER 2619 Specifications

General

Brand	BRUEL & KJAER
Model	2619
Category	Amplifier
Language	English