BRUEL & KJAER 2209 User guide

+ · Typ•2209
Impulse Precision Sound
Level Meter Type 2209
A compact and portable instrument
for precision sound and vibration
measurements. It conforms to IEC 179
for Precision Sound Level Meters,
the proposed IEC Recommendation
for Impulse Precision Sound Level
Meters and to DIN 45 633 parts 1
and
2.

IMPULSE PRECISION
SOUND LEVEL METER
TYPE
2209
December 1 973

CONTENTS
1. INTRODUCTION
7
1.1. Description of 2209 ... .............. ... .... ..... ....... .. ......... 7
1.2. Precision
Sound Level Meter Standards ...... ........... .. . 7
1.3. Impulse Sound Level Meter Standards ...................... 8
2. CONTROLS ........................................................................ 10
Meter Scale ........... ................................................ 10
Meter Switch ......................................................... 11
Weighting Network Switch .. .... .. ...... .. ........... ...... .. ... 11
Input Socket Switch .................. .. ...... .. ................... 12
Input Attenuator (black) .... .. ..... .. .. .. ................ .. .. .. .. .. 12
Output Attenuator (transparent) ............................... 12
Attenuator Scale ...... .. .. .. ........................................ 12
Gain Adjustment .................................................... 13
Overload Indicators .... .. .. .... .. .... ...... .. .. ......... ...... ..... 13
Meter Reset Button .. .. .. .. .. .... .. .. .... .. .. .. .. .... .... .. .. .. .. .. 13
External Filter Input and Output Sockets ...... ...... .. .. .. . 14
DC Output ........ .............................. .. ....... .... ....... ... 14
AC
Output .... ........... ........ ... ........ . .......................... 14
Pilot Light (Power) .................................................. 14
3. OPERATION ....................................................................... 15
3.1. Battery Replacement and
General Considerations .. .... .. .... ....... .. .. .. .... .. ....... ..... 15
Battery Replacement .... .. ..... .. .. .... ..... .. .. .... .. ........ .. .. 15
General Considerations .. .... .. .... .. .. .... .. ...... .... ......... .. 15
3.2 . Calibration for Sound Measurements ........................ 15
Using the Sound Level Calibrator or Pistonphone ....... 15
Using
the built-in Reference Voltage ........................ 17

3.3. Sound Measurements ............................................. 18
General Considerations .. .. .. .. .. .. .. .. .. .. .. .... .. .. .. ........ .. . 18
Specific Sound
Measurement Procedure ................... 19
3.4. Calibration for Vibration Measurements .................... 20
Using Accelerometer Calibrator 4291
Using the built-in Reference Voltage ........................ 22
3.5. Vibration Measurements ......................................... 23
General Considerations ........................................... 23
Specific Vibration Measurement Procedure .. ...... .. .. ... 24
3.6. Voltage Calibration and Measurement ...................... 25
4. DESCRIPTION ................................................................... 26
4.1.
4.2.
4.3.
4.4.
4.5.
4.6.
4.7.
4. 8.
4.9.
4.10.
4.11.
4.12.
Condenser Microphone ........................................... 26
Input Stage ........................................................... 28
Attenuator I and Input Amplifier ............................... 30
Reference Oscillator ............................................... 30
Overload Indicators ................................................ 30
Weighting Networks ............................................... 31
Attenuator II and Output Amplifier ........................... 31
RMS Detector ........................................................ 31
Impulse Detector .................................................... 33
Peak Detector ........................................................ 34
Hold Circuit ........................................................... 35
Power Supply ........................................................ 36
5. OPERATIONAL CHARACTERISTICS
AND ACCURACY ............................................................... 37
5.1.
5.2.
5.3.
5.4.
5.5.
5.6.
5.7.
5.8.
5.9.
5.1 0.
5.11.
5.12.
Directional Characteristics ....................................... 37
Random Incidence Response ................................... 43
Reflection . .. .... .. .. .. .... .. ........ .. .......... .. ..................... 43
Effect of Background Noise ...................................... 44
Input Capacitance .................................................. 45
Distortion ..... .. .. .... .. .... .. .... .. ............. .. .. .. .. .............. 46
Crest Factor Capabilities ......................................... 46
Temperature .......................................................... 49
Humidity ............................................................... 50
Inherent Noise Levels .. .. .. .. .. .. .. .. .. .. .. ........ .. .. .. .. .. .. .. . 51
Sound • .................................................................. 52
Vibration ............................................................... 53

50130 Pressure Oo 00 00 00 00 00 00 00 00 00 0000 00000000 000 00 00 00000 00000000 0000 0000000 59
50140 Wind 000 00 00 00 00 00 00 00 0000 00 00 0000 000000 0 00 00 0000 00 000000 0000000000000000 59
50 1 50 Electrostatic Fields 0000000000000000000000000000000000000 0. 0. 00000000 60
50 160 Magnetic Fields 000000000000000 0. 0. 00 0. 0. 0. 000000 0. 0. 000000 0. 00000000 60
50 17 0 Weighting Networks 0.0 0. 00000.. 000 0. 000.. 00..00000000000000000 0. 00 61
50180 Attenuator Frequency Characteristics 000 ooooooooo 00 00000 000 0 62
6. ACCESSORIES AND MEASURING SETS ............................ 63
601 0 Accessories Included with 2209 00000000000000000 00 000 0. 0... 0. 65
Adaptor JJ 2614 ........................... o ....................... 65
Half-inch to one-inoch Adaptor DB 0962 ···· '- ·············· 65
Flexible Extension Rod UA 0196 ..... ....... 0.. 0.....o ........ 65
Half-inch to one-inch Adaptor DB 0375 ................... 65
Random Incidence Corrector UA 0055 ····o····oo•·o···o··· 66
Windscreen UA 0207 ........... .. ........................ 0 ....... 66
Plugs JP 0006 .. 0. 0 ..... 0.......0 ........ 0 .......... 0 ....... 0 ....... 67
Attenuator Scales .................................. .......0 ••••••• 67
6020 Optional Accessories ..o.. o ....... o.. o·············o·····o·o······· 67
Octave Filter Set 161 3 .....0.....0 ...... 0.. . ..................... 67
Third Octave Filter Set 1 616 ........ .. ......... .... ........... 0 68
Adaptor JJ 261 5 Oo .o. 000 o•·o·· 000 Oo ...0o ........................... 69
Integrator ZR 0020 .. 0.. 00 ......... . ..... ... ........... 0....0 ...... 69
Accelerometers 0 ...................... 0 ............................. 0 70
Microphones .. . .... 0... ....... 0.......0 ........... 0.. 0.....0 ...... 0.. 70
Microphone Adaptors ..... .. o•· 0 •••••••••••••••• o ............. . o.o 71
Accelerometer Calibrator 4291 o·· ·· ··········· ·······o········ 72
Artificial Ears 41 52/53 ......................... 0......... ..... 0. 72
Artificial Mastoid 4930 0 ......................... 00......0 ........ 72
Connection Cable AO 0007 ....... .. ...... . ........ 0 ........ 0.. 72
Carrying Case KE 0055 .. ............ ........... .. ....... ........ 72
6030 Complete Measuring Sets ··0····0······························· 73
Sound and Vibration Sets Types 3507 and 3511 ...... 73
Audiometer Calibration Sets Types 3508 and 3512 .. o 74
7. USE WITH OTHER INSTRUMENTS ..................................... 75
7.1 0 Systems Considerations .......................................... 75
7 0 20 Level Recorders oo···ooo····o·······oo······o····o··················· 76
AC Recording ·····o········o······o·································· 76
DC Recording 00....0...0 0. 00..0 ......... 0 ............................ 76

7.3. Noise Nose Meter ........ .. .... .. .. .. .. .. .. .. .. .. .. .. .. .. .... .. .. .. 77
7.4. Tape and Digital Recording
...................................... 78
7.5. Analysis ................................................................ 78
7.6. Loudness Evaluation ............................................... 78
7.7. Maximum Acceleration ........................................... 78
8. SPECIFICATIONS ............................................................... 79
8.1.
8.2.
8.3.
8.4.
8.5.
8.6.
8.7.
8.8.
8.9.
8.1 0.
8.11.
8.12.
8.13.
8.14.
8.15.
8.16.
8.17.
8.18.
8.19.
8.20.
8.21.
8.22.
Frequency Response .............................................. .
Dynamic Range
..................................................... .
Input Stage .......................................................... .
Weighting Networks .............................................. .
External Filter Sockets
.......................................... ..
Output ................................................................. .
AC
Output ............................................................ .
DC Output ............................................................ .
Meter Damping ..................................................... .
Meter Indication .......... . ......................................... .
Inherent Noise ...................................................... .
Polarization Voltage
............................................... .
Overload Indicators ............................................... .
Calibration
........................................................... .
Sound
Measurements ............................................ .
Vibration
Measurements ....................................... ..
Sound,
Vibration and Voltage Measurements ........... .
Directional Characteristics
................................... ....
Effect
of Sound Field on Amplifiers ......................... .
Effect
of Static Pressure ........................................ ..
Effect
of Magnetic Field ........... . ............................ ..
Effect of Humidity .....· ........................................... ..
Operating
Temperature .......................................... .
Batteries
............ . ................................................. .
Dimensions .......................................................... .
Weight ...... ............ . .............................................. .
Accessories
.......................................................... .
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1. INTRODUCTION
1.1. DESCRIPTION OF 2209
The Bruel and Kjrer Impulse Precision Sound Level Meter Type 2209
is a compact, portable instrument for precision sound and vibration
measurement . It is designed to meet all current standards set by the IEC
for both Precision Sound Level Meters and Impulse Sound Level Meters.
The 2209 is designed so that in the impulse mode, its response char-
acteristics to short duration sounds (1 to 1 000 milliseconds) approximate
the response of the human ear . Thus it effectively measures the subjec-
tive loudness of short duration sound as heard by the human ear. The
impulse response characteristics meet all applicable IEC and DIN stand-
ards.
The 2209 is capable of measurements over a wide frequency and dy-
namic range. In addition, it can accurately measure the RMS values of
signals with crest factors up to 40 and also the peak values of signals
with duration greater than 20JJS. Built into the instrument are the A, B,
and C frequency weighting networks plus the D weighting network for
aircraft noise measurement.
With a wide range of accessories the 2209 is a versatile portable in-
strument. With the addition of the Third Octave Filter Set 1616 it be-
comes a portable, self-contained third octave measuring system.
1.2. PRECISION SOUND LEVEL METER STANDARDS
The IEC (International Electrotechnical Commission) has set various
standards for sound level meters. IEC Publication 1 23 gives the require-
ments for general purpose Sound Level Meters which are made more
stringent in Publication 1 79 for Precision Sound Level Meters. The
B & K
2209 meets or exceeds all requirements of IEC 179, the main
points of which are given below :
Free-field sound pressure level measurement accuracy of± 1 dB.
7

Essentially omnidirectional microphone characteristics (see sec-
tion 5.1). Square law type measurement indication.
Tolerances on meter scale calibration and range shift error are
specified.
- A "Fast" meter dynamic characteristic: R-esponse to ~ a 200 millisec-
ond pulse within -2 and 0 dB of the indication for a continuous sig-
nal of same frequency and amplitude. Damping such that overswing
on a suddenly applied steady signal is between + 0,1 and + 1,1 dB
An alternative "Slow" meter characteristic (optional): Response to a
500 millisecond pulse within -5 and -3 dB of the indication for a
continuous signal of same frequency and amplitude. Damping such
that overswing on a suddenly applied steady signal is between + 0,1
and + 1,6 dB compared to final steady indication (which must be
within 0,1 dB of level indicated with "Fast" characteristic).
Specifications are also given for frequency range capabilities, and
maximum permissible sensitivity to external and environmental in-
fluences.
The IEC publication specifical!y states that the Precision Sound Level
Meter is designed to give objective measurements which under certain
conditions approximate the subjective impression of sound. The 2209
meets all applicable IEC criteria and can be used for the measurement
of rnost continuous sounds.
1.3. I MPULSE SOUND LEVEL METER STANDARDS
Th e purpose of the impulse response circuit is to approximate the rise,
averaging, and storage time characteristics of the human ear for short
duratio n sounds. Both the German Standard DIN 45 633 part 2 and the
IEC draft for the extension of Publication 179 make similar specifica-
tions for Impulse Sound Level Meters. The 2209 conforms to all of
these and the main points of the IEC draft are given below:
8
Impulse Sound Level Meters must have same response characteris-
tics to steady sinusoidal signals as specified for Precision Sound
Level Meters.
Overload indicators at input to filters and at input to meter rectifi-
ers.