2
These factors, together with the flow
chart shown in
Fig. 1
, will help you
to make the right decision.
Measurement Standards
You can use these microphones in
noise measurement systems satisfy-
ing either ANSI or IEC standards (or
their local equivalents). The micro-
phones use 50% to 70% of the toler-
ances allowed by these standards.
Frequency Ranges
All six microphones cover the audio
frequency range. If, however, you
want to measure at frequencies down
to 0.05 Hz (for infrasound measure-
ments), choose the Type 4193, or at
frequencies up to 40 kHz (for harmon-
ic distortion measurements on loud-
speakers) choose the Type 4191.
Polarization/Preamplifier
Prepolarized microphones are re-
quired on certain portable sound lev-
el meters (which do not provide
external polarization) and are a good
choice in tough and humid environ-
ments. Externally polarized micro-
phones are more stable even at high
temperatures. All six can be used
with the
1
/
2
″
Microphone Preamplifi-
er Type 2669. The two prepolarized
microphones can also be used with
the Preamplifier Type 2671.
Free-field Response or Pressure-
field Response
The four free-field response micro-
phones (Types 4188 to 4191) cover
specific IEC requirements and should
be used in sound fields where reflec-
tions are negligible. The two pres-
sure-field response microphones
(Types 4192 and 4193) should be
used for measurements in acoustic
couplers. They also cover specific
ANSI requirements and can be used
in diffuse sound fields.
As Replacements for Earlier
Brüel&Kjær Microphones
Table 1
shows what earlier
Brüel & Kjær microphones can be re-
placed (type approval permitting) by
Falcon
Range microphones.
Prepolarized Free-field
1
/
2
″
Microphones Types 4188
and 4189
These are prepolarized, free-field mi-
crophones which differ mainly in fre-
quency range and sensitivity. Both
can be used for measurements in ac-
cordance with IEC 651 Type 1. The
Type 4188 is also suited to ANSI S
1.4 – 1983 Type 1 measurements
when fitted with the Random-inci-
dence Corrector DZ 9566 supplied. If
your measurements require only fre-
quency weighting (A or C), the Type
4188 is the more economic choice, and
is also more robust. The Type 4189
has a greater sensitivity and frequen-
cy range and is well suited to general
sound measurements requiring fre-
quency analysis.
They offer some significant advan-
tages when used with portable, low-
power instruments not designed to
produce a polarization voltage. An-
other advantage is greater reliability
of the associated preamplifier under
humid and polluted conditions. These
factors make these prepolarized con-
denser microphones particularly suit-
able for field measurements, both
outdoors and in industrial environ-
ments.
Earlier
Microphones
Falcon
Range
Mics.
4155
4189
4165
4190
4133/4149
4191
4134
4192
4147
4193
4166
(4188/4190/4192) *
4176
(4188/4189) *
Table 1 Replacement check for earlier
Brüel & Kjær microphones. The * means
these are not direct replacements
Fig.1 Flow chart to help you choose the right microphone from the Falcon
Range for your needs
940369e
Start
ANSI
S 1.4 1983
Type 1
or S 1.12
Type M
No
Yes
IEC
Pressure-
field
Free-
field
Audio
freq.
No
Extended
freq.
Yes
Type 1
Type 0
and
Type 1
S 1.4
Type 0
Type 1
External
Polarization
Audio freq. or
Extended freq.
Free-field
or
Pressure-field
Infrasound
Standards
ANSI
or
IEC 651
Frequency
Analysis
No
No
4188
4189
Yes
Yes
4190
4191
4192
4193
4188
4189
4190
4191
4192
4193
4188 + DZ 9566
4191
4192
4193
S 1.12
