BRUEL & KJAER 4152 Instructions And Applications page 6

24.-9.-1949 (but not in the present 3.3-1960 A.S.A. Standard), and the German
Standard Din 45600, and when using the 6 cm3 coupler, the force may be
adjusted to 500 grammes as prescribed in A.S.A. Standard Z. 24.-9.-1949
Figs. 3 and 4.
Retaining spring
arrangement
Coupler
Adopt or
(00 0111)
Microphone
Cartridge (4132)
Coupler
Adjustable
retaining
spring
support
f6371if
Fig. 1.2. Sectional view of the Artificial Ear and the Condenser Microphone .
Fig. 1.2 shows a sectional view of the socket with the mounting arrangement
for the condenser microphone. The guard ring (internal shield) principle
used in the Cathode Follower Type 2612 and 2613 is extended to include the
socket which keeps the effective transmission loss of the 4152 as low as
approximately o.1 dB.
As indicating meter, the Cathode Follower Type 2612 or 2613 and the Micro-
phone Ampiifier Type 2603 can be used as well as the Sound Level Meter
Type 2203. See Fig. 1.3.
The 2 cm3 Coupler.
One of the couplers supplied with the Artificial Ear Type 4152 is a 2 cm3
Coupler (DB 0138) which fulfils the requirement of International Standard
(I.E.C. Recommendation Publication 126). A sectional view of the ,Coupler
is shown in Fig. 1.4.
4