BRUEL & KJAER 2221 User Manual

3.3. MOUNTING THE MICROPHONE
The microphone is screwed directly onto the preamplifier, using light finger torque. Note
that the protection grid is not removable on this type of microphone. A fine wire gauze fil-
ter behind the protection grid prevents dust and particle penetration to the diaphragm.
The assembly may be plugged directly into the Instrument via its 5 pin DIN plug (see
Fig.3.2)
or connected via a 3 m or 10 m extension cable available under order numbers
AO 0185 and AO 0186 respectively. The microphone end of the extension cable has a
threaded attachment to enable it to be connected directly to a standard tripod screw. This
arrangement allows the operator to remain close to the Sound Level Meter for reading
purposes, while at the same time enabling him to be well away from the microphone, and
therefore not influence the . sound field.
Fig. 3.2. Mounting the microphone
3.4. CALIBRATION
10
The Sound Level Calibrator Type 4230 is used for acoustical calibration of the whole
Sound Level Meter, including the microphone.
Due to the quality of the instrument, calibration should only be necessary from time to
time and should require very little adjustment. If a large adjustment is needed, the
instrument is most probably defective and has to be checked for faults (Consult your
B & K representative).
The Type 4230 gives a nominal sound pressure level of 94 dB ± 0,3 dB (re. 20 x 10-6 Pa).
The
calibration procedure is as follows:
1. Remove the Random Incidence Adaptor or the Windscreen if fitted.
2. Set the controls on the Sound Level Meter as follows:
FUNCTION: "Leq"
RANGE: "45 - 1 05"
MODE:
"Run"
POWER: "On"

BRUEL & KJAER 2221 Specifications

General

Brand	BRUEL & KJAER
Model	2221
Category	Measuring Instruments
Language	English