Use Of Protecting Cover In The 6 Cm; Coupler - BRUEL & KJAER 4152 Instructions And Applications

Use of Proteetlng Cover in the 6 cm 3 Coupler.
To avoid damaging the diaphragm, when the 6 cm
3
coupler is used, it is
recommended to use the microphone with the normal protecting cover.
The coupler volume is then enlarged compared with the volume when the
microphone with the adapter ring DB 0111 is used, and the acoustical effect
COOOOOOOOOOO OOOOO O O O ODOOODOODD D OOCCOODOD Do oaODOOOD
----
..
a
c
...
~ ---
- -----
~~
--
" ~-
~
. .
- - -
.... .
_ - -
......... f _ _
~ ,_ ~o
or
1123
1)
100 1000 10000
Fig. A5. Curves showing the effect of supplying the micropllOne with protection
cover when used
in
the NBS type
9
A - Coupler.
a) No protection cover on the microphone.
b) Microphone su.pplied with the normal B &: K protection cover.
c)
Microphone supplied with the normal B &: K protection cover and with vase-
line between protection cover and microphone.
of this arrangement is a change in impedance of approx.
0.8
dB of the
coupler up to
1000
Hz, and above that frequency, the curve corresponds
within 0.3 dB)n the used frequency range to the curve recorded in agree-
ment with the standard. The curves are shown in Fig. A5.
B&K Protection
The diaphragm cover
~~~5T
The
gOp----- ~~~~~~~~~t_The
volume
-163760
Fig. A6. Sectional view of the microphone.
22