BRUEL & KJAER 2203 User Manual

curve and sens1t1v1ty data (individu-
ally determined for each micro-
phone) is supplied with the sound le-
vel
meter . The microphone is ex-
tremely reliable and unaffected by
humidity and temperature variations
over a wide range. The diaphragm
is quartz-coated to offer protection
in humid and corrosive atmos-
pheres, and back-venting allows it
to be used with the Dehumidifier
UA 0308 for further protection in
humid environments. The sensitivity
of the microphone is typically
50 mV per Pa ( 5 mV / J.lbar) with a
polarization voltage of 200 V.
Amplifier
The input stage of the amplifier
has an extremely high input imped-
ance, to match the high impedance
of the condenser microphone. Each
of the three sections of the follow-
ing amplifier is preceded by an at-
tenuator, the setting of these being
controlled by the two concentric
measuring range selectors on the
front of the instrument . External fil-
ters can be inserted between the
first and second sections, or the
built-in weighting networks, A, B
and
C, can be switched in. In the
linear position, where the weighting
networks are bypassed, the fre-
quency response of the instrument
is linear from 10Hz to 40kHz to
within ± 2 dB.
The
amplifier output section is
equipped
with an output socket mak-
ing it possible to use the instrument
in conjunction with a level recorder,
tape recorder etc .
The
supply voltage for the amplifi-
ers and the microphone polarization
voltage are produced by a built-in
oscillator.
dB SPL
80
lf
1\
\
70
lA
~~ ~
v
:I
60
. .
.,.
' '
' .
....
1 ~\iJ
50
20
50
1\
~ J I
N
~ ~ ~~ ·
~~~~
100 200
lt
,_.. . ,
~
.
t 1 ms -
2
~
~~
r
~~~~
500 1 kHz
7 6016 2
Fig. 15. Equivalent sound pressure level
when complete sound level meter is
excited vertically at 1 m / s 2
6
dB
+6
+4
+2
0
- 2
- 4
- 6
- 8
- 10
-12
1'--...
~
.....__
......
....I-
-
- ..
__ .....
' ..
I
I I
I
T I
I
ANSI S1,4 - 1_971,.--
v
Type 1
1--
~-
n
~~
'\.'
I
I
10 20 100 200 Hz 2 kHz 10 20
Frequency 760156
Fig.13. Diffuse field (random incidence) frequency response of complete instrument
+
2
Meter
deflection (dB rei. to continued signal level)
I
1 r
-
--
1
'1-ol~ran~e
1
""
v
I.-
/
IEC "Fast"
~
0
- 2
v
l/.
~ Tolerance
'/
IEC " Slow"
II'
1/
-4
- 6
/
/
/
/
- 8
~
/
v
- 10
" Fast"
~
"Slow " /
/
- 12
""
/
~
- 14
,
r
----
Ill
II
- 16
-18
- 20
-rtl t It+-
·t
1
=
1
2
k~z
II
I
2 5
10
2
5
100 2
5
1000 Pulse length t (ms)
76 0164
Fig.14. Response of meter rectifier and meter to tone bursts of varying duration
Meter and Rectifier Circuit
The meter rectifier circuit is of
the RMS type and is equipped with
two meter damping characteristics,
"Fast" and "Slow" in accordance
with the standards for precision
sound level meters. Fig.14 shows
their response to tone bursts as a
function of pulse duration .
The meter is a ribbon-suspended,
moving coil type. The meter scale is
graduated from -1 0 to + 1 0 dB for
dB SPL
70
60
! ~
50
~~' .
fill ~
40
20
j
~
~
50
I !~
' •
:
~ ·
~
:~
/ ~
' I
100
__ ...._ I
I
1
~
~
.:
200
!1111111" , I I
1 ms -
2
! ~
V:l
11
~~~ I
500 1 kHz
76016 1
Fig. 16 . Equivalent sound pressure level
when complete sound level meter is
excited horizontally at 1 m / s 2
reading of sound or vibration level.
A smaller scale is provided for cali-
bration of the instrument. to read
correctly with microphones of differ-
ent sensitivity using the built-in ref-
erence voltage and K-factor given
for each microphone . Battery condi-
tion can also be read on the meter.
To facilitate measurements in dim
or badly lit places, a meter light can
be
switched on by means of a
spring- loaded pushbutton .
Equivalent
SPL
dB Volts RMS
145
20
Microphone directly mounted
I I I
""l
140
10
I I I
~'\.'\.
L10% distortion~
~
'---- 5% distortion
5
- 1% distortion
lith J abl l A ~ 0128\
~
I
\
2
135
130
125
20 100
1000
10000
Hz
Frequency
1 13 496 / 1
Fig . 17. Distortion as function of input vol-
tage

BRUEL & KJAER 2203 Specifications

General

Brand	BRUEL & KJAER
Model	2203
Category	Measuring Instruments
Language	English