HBK 4231, User Manual

Page: 17 / 94

Chapter 2 – Operation
9 Sound Calibrator Type 4231
User Manual
Table 2.1 Calibration levels for various sound fields and sizes of Brüel & Kjær microphones
(SPL at 94.0 dB level)
✐
Please note:
• If you have increased the sound pressure level to 114 dB, by using the
level step button, please note that you should add 20 dB to the figures
in Table 2.1.
• A sound field correction may automatically be included in the
calibration routine of the sound level meter. If in doubt, consult the
instruction manual for your sound level meter. For Brüel & Kjær sound
level meters Type 2245, 2250, 2250-L and 2270, the correction is
included.
Sound
Field
Microphone
1

1/2

1/4

1/8

Free-field
93.70 dB 93.85 dB 94.00 dB
Random
94.00 dB
Pressure
94.00 dB