(Tracable to the german national reference)
I. Pressure sensitivity for measurement microphones acc. to IEC 1094-2, -4 , -5
|
Microphone types, e.g.
|
Uncertainty
(1000 Hz)
|
Procedure
|
Typical duration
|
Frequency range
in Hz
|
B&K 4180, 4134, 4192
GRAS 40AG,
..........
|
0,1 dB
|
Comparison
|
5 days
|
125 - 16000
(17 frequencies)
|
|
0,06 dB (250 Hz)
|
Reference to sound calibrator
|
5 days
|
250 and 1000
|
B&K 4144,
LD 2575
.......
|
0,1 dB
|
Substitution
|
5 days
|
125 - 8000
(11 frequencies)
|
|
0,05 dB
|
Reciprocity
|
4 weeks
(on request)
|
31,5 - 10000
(23 frequencies)
|
|
B&K 4136
|
0,12 dB
|
Comparison
|
5 days
|
63 - 20000
(26 frequencies)
|
|
B&K 4160
|
0,03 dB
|
Reciprocity
|
4 weeks
(on request)
|
31,5 - 10000
(23 frequencies)
|
|
B&K 4180
|
0,06 dB
|
Reciprocity
|
4 weeks
(on request)
|
63 - 20000
(26 frequencies)
|
|
B&K 4134
|
0,06 dB
|
Reciprocity
|
4 weeks
(on request)
|
63 - 20000
(20 frequencies)
|
On request, microphones can be calibrated at higher or lower frequencies.
II. Sound pressure level of sound calibrators
Type |
Measurement uncertainty |
Measuring technique |
Typical test time |
Frequency range in Hz |
| Single frequency calibrator |
0,05 dB - 0,2 dB |
with calibrated microphone |
7 days |
250 / 1000 |
| Multifrequency calibrator |
0,10 dB - 0,25 dB |
with calibrated microphone |
7 days |
16 - 16000 |
On request, sound calibrators can be calibrated at higher or lower frequencies.
|
