Removing the Anthropometric Pinna
As the Anthropometric Pinna is screw-mounted onto the RA0045 Ear Simulator, this assembly
must be removed from the 45CA before the pinna can be separated from the ear simulator.
1.
Loosen the screw holding the ear simulator, see Fig. 7 on page
22.
2.
Gently pull out the assembly.
While holding at the centre of
the pinna - with a finger in the
ear canal - gently pry outwards
Do
not
pull at the ear lobe as
pulling here repeatedly may
damage it
Fig. 8.
Showing where to pull when removing the ear si anthropometric pinna from 45CA.
Pressure Equalization
45CA is furnished with capillary equalization tubes that connect the cavity under the ear muffs to
the external air. When these tubes are not sealed, the pressure build-up that will occur when you
fit the ear-muffs will be equalized.
However, before measuring according to ISO4869-3 you may have to close the tubes after having
fitted the hearing protector. For this purpose, two 6 mm M3 grub screws are part of the delivery.
These are mounted at the bottom of the 45CA test fixture head.
Pressure equalization
tubes
M3 x 6 grub screws for
closing the tubes
Fig. 9.
Showing where to close and open the pressure equalization tubes.
The screws seal after a few turns.
Instruction Manual
45CA Headphone/Hearing-protector Test Fixture | 2 3