BRUEL & KJAER 2221 User Manual

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4. Connect the AC OUTPUT of the Sound Level Meter to the SIGNAL INPUT socket of
the Level Recorder using the cable AO 0173
5. Place the Sound Level Calibrator Type 4230 onto the microphone and check the
calibration (93,8 ± 0,1 dB on display; see section 3.4).
The difference between the reference level and the maximum range value is
125 - 93,8
= 31 ,2 dB.
6. Set the PEN DRIVE, PAPER DRIVE and POWER switches to "On".
7. Start the Sound Level Calibrator and adjust the SENSITIVITY knob of the Level
Recorder to obtain a pen deflection of 31 ,2 dB below full scale line of the recording
paper (see Fig.4.2).
~DDDDDDODODDDDDDDDDODD
125
Bruel & Kjcer
Scale top
1---- -
115
31,2
105
95
93,8
85
Scale bottom
75
811404
Fig. 4.2. Calibration of the Level Recorder Type 2306
The pen deflection of the Level Recorder is now calibrated and full scale on paper
corresponds to the maximum of the measurement range selected on the Sound Level
Meter. Do not readjust SENSITIVITY. The recording amplitude on the paper is determined
by the range potentiometer fitted to the Level Recorder (50 dB).
Note: The three positions Leq• SEL and Max. Hold "Fast/Slow" will give the same A-
weighted signal at the AC OUTPUT. The Max. hold "Peak" position will give the L-
weighted (Linear) signal. See Fig.4.3.
ODDDDDDDDDODODDODDDD
DDDDDDDODDDDDDDDODDO
r:::dB(A)
~95
t=::=85
l:=75
~65
55
QP 0102
Fig. 4.3.
Bruel & Kjcar
a
~dB( lin.)
~95
85
75
65
55
Bruel & Kjcar
b
811434
a) Examples of recording with A-weighting (Leq, SEL,
Fast/Slow)
b) Examples of recording with Linear weighting

BRUEL & KJAER 2221 Specifications

General

Brand	BRUEL & KJAER
Model	2221
Category	Measuring Instruments
Language	English