4
LI0107 - Revision 7 September 2012
Fig 1.3
Free-field corrections for various angles of incidence on the ½
"
microphone
Fig 1.4
Typical noise floor of Type 40HL for system
and microphone. Shown in
⅓
-octave bands for both the
linear and A-weighted cases.
Fig 1.2
Typical frequency response curves of Type 40HL
•
either Pistonphone Type 40AP (recommended due to its built-in precision barometer) or
Pistonphone Type 40AA
and
•
Calibration Adapter RA0090 for attenuating the pistonphone signal to 94 dB re. 20 μPa.
See also the section
What to Order.
100 kHz
10 kHz
1 kHz
100 Hz
Decib
els r
e. level at
250
Hz
- 6
- 4
- 2
0
2
4
6
8
10
180 º
Random incidence
150 º
120 º
0 º
30 º
60 º
90 º
0 º
90 º
120 º
- 8
14
12
