
1.89 mm
Insert
GR0970
Grub screws for holding the
microphone in position.
Use Allen key, 2.5 mm, YY0016
G.R.A.S. SOUND & VIBRATION
Page 13
Hearing-Protector Test Fixture Type 45CA
Fig. 4.11 Correct position of the Microphone Type 40EN relative to the slanting plane of
the head
9.
The last step is to ensure correct microphone positioning:
Figure 4. of ISO 4869-3 shows that the center of the microphone’s diaphragm must be
level in the vertical plane with the slanting surface of the head.
For Microphone Type 40EN, this will be the case when the center of the protection grids
sticks out by 1.89 mm in the vertical plane with the slanting surface of the head.
Use the grub screws to pinch the microphones
lightly
to hold them in position.
Note:
If you cannot get the microphone positioned to the correct depth, loosen the four
screws on the face and the single screw on the inlay. Then, gently maneuver the
microphone into place, taking care not to push it completely into the cavity.
Содержание 45CA
Страница 2: ...Revision 28 November 2013 LI0024 ...