User manual

159
Calibration
Free-field Correction
The following free-field correction shall be applied using the
NTi Audio Class 1 Sound Calibrator
M2230, M2211, M2215: -0.1 dB•
The following correction shall be applied using the NTi Audio
Class 1 Sound Calibrator with 1/4” adapter ADP 1/4-P
M4260: +0.1 dB•
M4261: +0.2 dB•
The NTi Audio microphones are free-field equalized measure-
ment microphone. Thus they already compensates the in-
creased level by the presence of the microphone body in the
free-field. Pressure conditions apply during the calibration.
Therefore, the level in front of the 1/2” microphone diaphragm
differs by -0.08 dB with reference ambient conditions.
M2230 with 50 mm Wind Screen •
The correction value is +0.12 dB and the XL2 has to be set
to a calibration level of 114.0 dB (=114-0.08+0.12).
M2230 with 90 mm Wind Screen •
The correction value is +0.19 dB and the calibration level on
the XL2 has to be set to 114.1 dB (=114-0.08+0.19).
M2230 with WP30 Wind Screen 90 mm •
The correction value is +0.19 dB and the calibration level on
the XL2 has to be set to 114.1 dB (=114-0.08+0.19).
Example - Field Calibration
Configuration•
XL2 + M2230 Measurement Microphone
-
NTi Audio Class 1 Sound Calibrator @ 114.0 dB
-
The level •
1
at User Calibration shall be set to 113.9 dB
(=114.0 - 0.1).
1
Select the parameter • RUN and press enter .
 The field calibration is completed.