Bruel & kjaer 2203 User manual

Instruction

Manual

Precision Sound Level

Meter

Type

2203

This

portable

sound

level

meter

complies

with

all

existing

standards

for

precision

sound

level

meters.

It

is equipped

with

an

individually

calibrated

condenser

micro-

phone,

an

internal

reference

voltage

for

cali-

bration,

"Lin",

"A",

"8",

and

"C"

weight-

ing

networks,

"Fast"

and

"Slow"

meter

re-

sponses, and an AC

output

for

connection

to

recorders, etc.. External

filters

can be

di-

rectly

attached,

!3nd

a

wide

range

of

acces-

sories

is available.

It

can also be used

with

an

accelerometer

for

vibration

measure

-

ments

.

+

Bri.iel

&Kjmr

PRECISION

SOUND

LEVEL

METER

TYPE

2203

Applicable

to

instruments

from

serial

no.

598

006

Reprint

April

1

977

CONTENTS

1.

INTRODUCTION

AND

SPECIFICATIONS

(PRODUCT

DATA)

.................................................

1

2.

CONTROLS

..

.... ....

..

.

....

.

..

.....

..

.

..

.

..

.

..

..........

..

........

..

....

..

....

..

.... ....

..

......

..

.. 9

3.

OPERATION

.........................................................................................................................

13

3.1.

BATTERY CONSIDERATIONS

..

.....

.

..........................................................

13

3.2.

GENERAL CONSIDERATIONS

..

.

..............

.

.................................................

14

3.3.

CALIBRATION

FOR

SOUND MEASUREMENTS .......

..........

.

..................

........

14

General

.......................

.

..........................................................................

14

Acoustical

Calibration (External Source) .....................................................

14

Calibration using

the

Internal

Reference Voltage ......................................... 15

3.4.

SOUND MEASUREMENTS .......

........

...........

................

.

...........

..

................

17

General

...............................

.

.....

.

.......

......

...............

.

............

.

..................

17

Procedure

for

Sound

Measurements

.......

..

............

..

...........

..

....

..

.. ..

..

.. ..

17

3.5.

CALIBRATION

FOR

VIBRATION MEASUREMENTS .....

................

......

...........

18

General

............

..

............

..

.........

.

..

.

.........................................................

18

Calibration using

the

Accelerometer

Calibrator Type

4291

........................... 19

Calibration using

the

Internal

Reference Voltage .........................................

20

3.6.

VIBRATION MEASUREMENTS

.................................

.

...................

.

............

20

General ......

.....................................

.. ..

.

...........

.. .....

..

..................

............

20

Procedure

for

Vibration

Measurements

......................................................

20

3.7

. CALCULATION

OF

VIBRATION AMPLITUDE

.....

.

........

.

.....................

.

............

21

With

4291

Calibration,

Without

Integrator

.................................................

21

With

4291

Calibration,

With

lntegratorZR

0020

..

............ ..

...............

..

.......

21

With

Internal

Calibration,

Without

Integrator

......

.........

....

..

.........................

23

With

Internal

Calibration,

With

Integrator

ZR

0020

..

......

..

.

..

..........

...........

.

..

23

FEATURES:

•

Complies

with

all

existing

standards

for

precision

sound

level

meters

•

Equipped

with

individually

calibrated,

high

sensitivity,

precision

condenser

microphone

•

Conical

shaped

front-end

for

minimum

disturbance

of

sound

field

•

RMS

detector

with

crest

factor

capability

up

to

5

•

"A",

"8",

"C"

and

"Lin"

frequency

weighting

•

Performs

as

Octave

or

Third-Octave

analyzer

with

system-matching

filter

sets

•

AC

output

for

recorders

etc.

•

Performs

as

Vibration

Meter

or

Analyzer

combined

with

appropriate

accessories

•

Wide

selection

of

accessories

16-

169

type

2203

Precision Sound Level

Meter

USES:

•

Acoustics,

measurement

of

sound

insulation,

sound

distribution

etc.

•

Noise

and

vibration

measurements

in

industry

for

quality

inspection

and

development

•

Noise

and

vibration

measurements

for

health

protection

•

Audiometer

calibration

The

Precision

Sound

Level

Meter

Type

2203

has

been

designed

as a

robust

compact

unit

able

to

perform

sound

and

vibration

measurements

of

almost

any

kind

with

the

highest

degree

of

accuracy

.

The

instrument

fulfils

the

requirements

of

IEC

1

79,

DIN

45

633

part

1 as

well

as

ANSI

S1.4- 1

971

Type 1

for

precision

sound

level

meters

and

includes

the

A,

B

and

C

weighting

networks

and

the

Fast

and

Slow

meter

responses

.

In-

and

output

sockets,

for

connec-

tion

of

external

filters

for

frequency

analysis

of

the

measured

signal,

as

well

as a

recorder

output,

for

con

-

nection

of

headphones,

level

record-

ers

etc. are

also

provided

. A

built-

in

reference

voltage

provides

easy

electrical

calibration

of

the

instru-

ment.

The

sound

level

meter

is

pow-

ered

from

three

standard

1,5

volt

batteries

giving

10

hours

of

continu-

ous

operation.

Longer

operating

times

can be

obtained

using

alka-

line

batteries

or

rechargeable

NiCd-

cells.

The

battery

condition

can

eas-

ily

be

checked

on

the

meter.

Sound

Measurements

As

standard

,

the

instrument

is

equipped

with

a B & K

high

sensitiv-

ity, 1/

2"

diameter,

free-field

Con-

denser

Microphone

Type

4165,

giv-

ing

it

a

measuring

range

from

26

to

140

dB(A)

and

a

wide

frequency

range,

both

in

free

and

diffuse

sound

fields,

due

to

its

excellent

om-

nidirectivity

.

The

microphone

is

de-

livered

with

its

own

individual

cali-

bration

chart

giving

all

relevant

cali-

bration

data

and

complete

fre-

quency

response

curve.

The

microphone

may

be

mounted

directly

on

the

instrument

but

should

normally

be

mounted

on

the

Extension

Rod

UA

0196,

which

is

included,

and

which,

together

with

the

conical

shaped

front

-

end

of

the

instrument

secures

the

omnidirE::c-

tional

characteristics

required

to

ful

-

fil

IEC, DIN

and

ANSI

requirements

for

precision

sound

level

meters

.

If

it

is

desired

to

remove

the

micro-

phone

even

further

from

the

instru

-

ment,

a 3

metre

Extension

Cable

AO

0128

is available. A

wind-

screen

is

supplied

with

the

instru-

ment

and

should

be

fitted

over

the

microphone

when

measuring

out

-

doors,

to

reduce

wind

noise

.

Also

in-

cluded

is

an

input

adaptor,

to

be

fit

-

ted

instead

of

the

mic

r

ophone,

al-

lowing

direct

electrical

input

,

for

in-

stance

from

an

accelerometer

for

vi-

bration

measurements,

or

from

a

hydrophone

for

underwater

sound

measurements.

The

instrument

can

measure

the

linear

sound

pressure

level as

well

as

the

standard

frequency

weighted

sound

levels.

Two

meter

response

times

in

accordance

with

the

stan-

dard

recommendation

s can be

chosen.

Use

with

other

Microphones.

For

the

measurement

of

higher

levels

2

co

"0

+20

+10

c A

5l

0

c:

0

~-10

.........

v----

~

-----

~

-

~

::::::::-.....

QJ

a:

~

-20

·;

~

-30

-

40

-50

-

60

v /

/ v

v /

/

v

-

70

10 2 5

/

...........

/

2 5 2 5 2

Frequency

Hz 1

682

17

Fig

.

1.

Frequency

response

curves

of

the

A.

B

and

C

weighting

networks

and

frequencies

than

is

possible

with

the

1/

2"

microphone

Type

41

65,

or

if

a

linear

,

random

inci-

dence

microphone

response

is re-

quired,

other

1/

2"

microphones

from

the

B & K

range

can be

used

directly,

for

instance

Type

4133,

4134,

4163

or

4166.

For

measurement

of

lower

levels,

the

1"

microphones

Type

4145

or

41 61 can be

used

.

Adaptors

DB

0962

and

DB

0375

are

available

for

fitting

these

Microphones

di-

rectly

onto

the

input

stage

or

onto

the

extension

rod

respectively.

In

or-

der

to

fulfil

the

standard

require-

ments

to

omnidirectivity,

the

1"

mic-

rophones

require

the

use

of

a

Ran-

dom

Incidence

Corrector

UA

0055

instead

of

the

normal

mi

crophone

protection

grid. For special

applica-

tions,

the

sound

level

meter

can be

used

with

other

microphones

than

described

here

and

the

Product

Data

Sheet

for

the

B & K

micro-

phone

range

should

be

consulted.

See

also

survey

of

accessories

avail-

able,

on

page 4.

Vibration

Measurements

When

the

microphone

is replaced

by

the

Input

Adaptor

JJ

2614

(in-

cluded)

and

one

of

the

B & K

acceler-

ometers

is

connected,

the

instru-

ment

functions

as a

vibration

meter

indicating

the

acceleration

level.

Connection

of

the

Integrator

ZR

0020

between

the

accelerometer

and

Sound

Level

Meter

permits

measurement

of

vibration

velocity

and

displacement

as

well

as

acceler-

ation

. A calcu.

lating

disc

delivered

with

the

Integrator

makes

conver-

Fig.2.

The

Integrator

ZR

0020

Fig.

3.

The

sound

level

meter

equipped

with

integrator

and

accelerometer

for

vibration

measure

-

ments

and

Octave

Filter

Set

Type

1613

for

frequency

analysis

sion

of

the

dB

reading

into

vibration

units

a

simple

matter

.

Calibration

Acoustical

calibration,

which

also

tests

the

microphone,

can

easily

be

performed

by

either

of

the

two

cali-

brators

available:

Pistonphone

Type

4220,

which

gives a SPL

of

1

24

dB

with

±

0,2

dB

accuracy

at

250Hz,

and

Sound

Level

Calibrator

Type

4230,

which

gives

a SPL

of

94

dB

with

±

0,25

dB

accuracy

at

1 kHz.

When

using

the

sound

level

meter

for

vibration

measurements,

com-

plete

calibration

can be

performed

by

means

of

the

portable

Acceler-

ometer

Calibrator

Type

42

91,

which

calibrates

at 1 g peak and

79,6

Hz.

Fig.4.

The

Pistonphone

Type

4220

and

Sound

Level

Calibrator

Type

4230

Audiometer

Calibration,

Hearing

Aid

Testing

When

the

microphone

is replaced

by an

Artificial

Ear Type 41

52

or

41

53

with

microphone

4144

or

41

34

respectively,

a precise, com-

pact

and

fully

portable

audiometer

calibrator

is

created

.

If

the

Artificial

Mastoid

Type

4930

is

connected

in-

stead

of

the

microphone,

measure-

ments

on

bone

vibrators

and

bone

conduction

hearing

aids can be

made,

and

if

the

sound

level

meter

is used

with

Hearing

Aid

Test

Box

Type

4217,

a

complete

test

facility

for

hearing

aids

is

created.

Frequency

Analysis

For

frequency

analysis

of

the

mea

-

sured

sound

or

vibration

level,

the

Octave

Filter

Set

Type 1

61

3

or

the

Third-Octave

Filter

Set

Type 161 6

Fig

.

5.

The

sound

level

meter

in

combination

with

Hearing

Aid

Test

Box

Type

4217

Fig

.6.

The

sound

level

meter

used

with

Arti

-

ficial

Ear

Type

4152

for

testing

ear-

phones

and

audiometers

is

attached

directly

onto

the

sound

level

meter,

and is

connected

electri-

cally

with

a

connection

bar

. Type

1

61

3

contains

t11 octave

filters

(with

adjustable

attenuation)

with

centre

frequencies

from

31,5

Hz

to

31,5kHz.

Type

1616

contains

34

third

octave

filters

with

centre

fre-

quencies

from

20Hz

to

40kHz.

Nar-

rower

band

frequency

analysis,

as

is

often

required

for

vibration

analy

-

sis, can be

made

using

the

battery

powered

Tunable

Band Pass

Filter

Type 1

621,

(or

the

Tracking

Filter

Type

1623.)

Field

Recording

When

measuring

in

the

field,

the

tedious

work

of

plotting

levels

with

a

pencil

can be

completely

elimi-

nated

by

use

of

the

small,

portable,

battery

operated

Level

Recorder

Type

2306

.

It

is

connected

via a

cable

to

the

output

of

the

sound

level

meter

and

can record

either

sound

levels as a

function

of

time

or,

if

the

sound

level

meter

is

equipped

with

a

filter,

sound

levels

as a

function

of

frequency

. For

time

recordings,

use can be

made

of

very

slow

recording

paper

speeds, so

that

diagrams

showing

sound

level

variations

over

longer

periods

of

time

can be recorded on a

reason-

able

length

of

paper

.

Such

charts

are

of

great

help

in

almost

any

type

of

noise

investigation

and ease

the

location

of

noise

events

with

re-

spect to

time

as

well

as

the

possible

source

.

Frequency

spectrograms

can

be recorded

directly

on

frequency

calibrated

paper,

and

can be

made

semi-automatically

in a

few

sec-

onds,

using

the

filters

Type

1616,

1621

or

162

3.

The

recorded spec-

trograms

and

time

histories

provide

immediate

documentation

of

the

measurement

made

and can be

in-

serted

directly

in

the

measurement

report.

If

further

investigation

of

the

measured

signal

is

required

back in

the

laboratory,

the

battery

operated,

portable

Tape Recorders Types

7003

and

7004

should

be used.

Fig

.7.

The

portable

Level

Recorder

Type

2306

Complete

Sets

The

sound

level

meter

can be

or-

dered

with

accessories according

to

requirement.

However,

to

simplify

ordering,

four

sets,

containing

the

most

commonly

used accessories,

have been

assembled.

There are

two

sets

for

sound

and

vibration

measurements

in

the

field, and

two

sets

for

audiometer

calibration,

the

difference

being

the

filter

included

(Type

1613

or

1616)

.

The

sets

combine

complete

porta-

bility

with

laboratory

accuracy

and

are

delivered

in

the

sturdy

fibre-

glass

carrying

case

KE

0055

which

has

separate

compartments

for

each

item

.

The

contents

of

the

sets

are

listed

on

page 5.

Accessories

A

wide

selection

of

accessory

equipment

is

available

to

expand

the

application

possibilities

of

the

sound

level

meter

. A

survey

show-

ing

how

the

most

useful

items

con-

nect

is

given

below

. For

more

infor-

mation

on

the

individual

instru-

ments

and

transducers

indicated,

please ask

for

separate

data

sheets.

VIBRATION

MEASUREMENT

Accelerometer

Calibrator

4291

AUDIOMETER

CALIBRATION

1"

Wind

Screen

.--J

UA

0207

Sound Le

vel

Calibrator

E:l

4230

SOUND MEASUREMENT

1/2"

Wind Screen

•

UA

0237

Pistonphone

I I I

4220

UNDERWATER

SOUND MEASUREMENT

Plug

Adaptor

JP

0028

AdaJ;1tor

~--~----

.....

Tape Recorder 7003

or

7004

-_____,

~

Typical:4338,4366,4367,

rg Accelerometers

~

4368,4369.

JJ

2614

Adaptor

.,_

_______

4iiiiOOI

-------1

JJ

2615

Integrator

~---~------~

ZR 0020 Control Cable.

1616-AO

0123,

1621-AQ

0035

Artificial

Ear

Artificial

Ear

Artificial

Mastoid

•J

~

Jlij

r;=

4153 4152 4930

*)

Microphone Extension

Cable

AO

0128 must

be

used

IO~:}_l

___

l

2306 Connection

~

DB

1021

It-I

Normal

0-----,

ting Grid

Protec

Ran

dom

Incidence Corrector

1"

Microphone

m

[)

UA

0055

Nose

Cone

<Jll---...J4161

Dehumi-

UA

0387

difier

UA

0310

No

rmal

D-----.

1/2"

Micro~

IIJ

Protecting Grid 4149 4165

4163 4166 Dehumidifier

UA

0308

Nose

1/2"

Microphone

Cone

1----[]

<JJ

---....J

4133

UA

0386 4134

Normal

Protecting Grid

Nose

Cone

UA

0385

Nose

Cone

1/4"

-

1/2"

Microphone Adaptor

D--

-

........

4135

UA

0035

4136

1/8"

-

1/2"

Microphone

Adaptor

---~---D--~

UA

0355

Hydrophone

Type 8100

Hydrophone

Type 8103

4138

UA

0036

Plug Adaptor

1/2"-

1"

Adaptor

DB 0962

1/2"

Extension Cable

AO

0128 - 3 metre

Connecting

Bar

JP

0400

~

(included

with

1613

and 1616)

2 Connection

Cables

A00116

Tunable

~

- -

-

..

·:

·

··

·

-·

.

.-

Filter

e

--

_

1621

.,

••

Cable

AO 0116

Precision

Sound Level

Meter 2203

Octave Filter

Set 1613 or

Third

Octave - - --l

Filter Set . I

1616 I

Tracking

Filter

LW--=y

1623

I

- _

_.J

Accessories included

with

2203 underlined

Fig.8.

Survey

of

accessories

available

for

sound

and

vibration

measurements

and

audiometer

calibration

4

Sound

and

Vibration

Sets

Accelerometer

Set

Type

4366S

standard

accessories

Type

2203

Type

3501

and

Type

3509

Nose

Cone

1I

2"

UA

0386

Octave

Filter

Set

Type

1613

Precision

Sound

Level

Meter

with

Adaptor

for

tripod

UA

0354

(3502

only)

standard

accessories

Type

2203

Integrator

ZR

0020

Third-Octave

Filter

Set

Type

1616

Octave

Filter

Set

Type

1613

Extension

Cable

AO

0128

(3510only)

(3501

only)

Carrying

Case

KE

0055

Pistonphone

Type

4220

Third

-

Octave

Filter

Set

Type

1616

Artificial

Ear Type

4152

(3509

only)

Audiometer

Calibrators

Type

3502

Microphone

1"

Type

4144

Pistonphone

Type

4220

and

Type

351

0

1"

Adaptor

DB

0375

Microphone

1I

2"

Type

4166

Precision

Sound

Level

Meter

with

Carrying

Case

KE

0055

Fig.9

The

Sound

and

Vibration

Set

Type

3501

Fig.

10.

The

Audiometer

Calibrator

Type

3510

Description

The

Precision

Sound

Level

Meter

Type

2203

contains

a

condenser

microphone

with

associated

polariza-

tion

voltage

supply

and

preampli-

fier,

a

low

noise

amplifier

and

a

me-

ter

circuit

with

moving

coil

meter.

A

built-in

reference

signal

provides

a

ready

check

of

the

amplifier

and

me-

ter

circuit

.

Microphone

The

B & K

Microphone

Type 41

65

employed

in

the

sound

level

meter

is a prec1s1on

condenser

micro-

phone.

It

is

designed

to

have a

lin-

ear

frequency

response

when

used

for

free-field

sound

measurements

where

the

sound

has

0°

angle

of

in-

cidence

(perpendicular

to

micro-

phone

diaphragm).

The

microphone

has

excellent

directional

characteris-

tics

over

a

wide

frequency

range

.

Characteristics

of

the

microphone

alone,

and

of

the

complete

instru-

ment

are

shown

on page 7. Figs.

12

and

13

show

the

frequency

re-

sponse

curves

of

the

complete

in-

strument

to

0°

incident

sine

waves,

and

in a

diffuse

field.

All

curves

are

well

within

the

requirements

of

the

relevant

standards

. A

calibration

chart

with

frequency

response

ndenser

Co

Mi

crophone

r----

~

dB

+6

+4

+2

0

-2

-4

- 6

- 8

-10

-1

2

-

..........

!"-..

v

10 20

Input

Stage

External

Filters

_1_

_!___

f I

1-

- - - - -

--

- - - - - -

-1

~

Attenuator

~

Amplifier

~

Weighting

Networks

•

Attenuator

•

Amplifier

~

Attenuator

~

I f I I I

I

Reference

Amplifier

RMS Meter

Oscillator Rectifier

1-

Output

172206

Fig.

11.

Block

diagram

of

Type

2203

v IEC

179-

""""'~

~~

... -

'

II'-"

"

......

~

...

\..

I

100 200

Hz

2

kHz

10 20

Frequency 760155

Fig.

12.

Free-field

frequency

response

of

complete

instrument

to

sine

waves

with

0°

incidence

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

,_..

. ,

~

.

t1

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

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

=12

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

+ 10 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

Directional Characteristics

i

160116

Fig

.

18

.

Directional

characteristics

of

the

microphone

Type

4165

in a

free

-

field

I

·IJ~~

--

~

-------

160171

Fig

.

19

.

Directional

characteristics

of

the

complete

instrument

inclusive

microphone

and

extension

rod

in

a

free

-

field

Specifications

2203

(Specifications

refer

to

2203

with

Extension

Rod

UA

0196

and

Microphone

·

4165,

unless

otherwise

stated)

Measuring

Ranges:

Weighting

Network

Minimum

Level (dB)

External

Filter

Type

No

.

Microphone

Max

.

Type No. Level

f---.---.--,.--+-----.--.;__-r----+----.,..---:__r---~---i

(dB)

161 3 (Octave)

161

6 (1/ 3 Octave)

0,5

to

0,5

to

A B C

Lin

1"

4144

,

4145

140

19

23

28

38

1/

2"fl-165,*4166

140

26

31

36

43

1/ 2"

f4133

,

4134

154

39

43

48

55

* Included in

2203

Frequency

Response:

(Microphone)*

(zero

degree

incidence

,

free-field)

±1

dB:

4Hz

to

12

,

5kHz

±2dB:

3Hz

to

20kHz

*)

individually

calibrated

Frequency

Response:

(Amplifier)

±

0,5

dB:

40Hz

to

25kHz

± 1

dB:

20Hz

to

25kHz

± 2

dB:

10Hz

to

40kHz

Frequency

Weighting

:

A, B

and

C

to

IEC 1

79

. (See Fig.1)

Input

Impedance:

> 2 GO/ /

2,8

pF

31 ,5

to

63Hz

25

;36

48

(with

extension

cable

AO

0128

> 2 GO/ /

3,2

pF)

Max.

Input

Voltage:

1

OV

RMS

(sinusoidal)

(See also

curves

Fig.

17)

Total

Amplification:

110dB

Attenuators

:

20

to

140

dB FSD in 10 dB steps, accu-

racy ± 0,2 dB

Output

Impedance:

<

1000

.

Maximum

load

10

kO

or 1

nF

for

less

than

0,2

dB

error.

Maximum

Output

Voltage

:

16V

peak,

(3,16V

RMS

for

FSD)

External

Filter

Sockets:

Output

Impedance:

<

50

in series

with

1

00tJF

Input

Impedance

:

146

kO

Inherent

Noise

:

Linear:

max

.

40

tJV

referred

to

input

Curve

A :

max

.

4tJV

referred

to

input

Detector:

RMS

Accuracy:

± 0,5 dB

for

crest

factors

be

low

3

± 1 dB

for

crest

factors

below

5

Meter

Damping

:

"

Fast"

and

"

Slow"

to

IEC 1

79

125

to

20

to

100

to

16

(31

,5)

16

(40)

250Hz

kHz

80Hz

400Hz

kHz

20

15

25 22 22

30

24

34

27

24

42

36

46

39

36

Meter

:

Graduation

:

1 dB

divisions

from

- 10 to 0 dB

0,

5 dB

divisions

from

0 to 10 dB

Accuracy:

0,

5 dB

for

deflections

below

0 dB

0,

2 dB

for

deflections

above 0 dB

Microphone

Sensitivity:

Lin

30

38

50

Approx

.

50

mV

/

Pa

individually

calibrated

Microphone

Temperature

Coefficient:

Approx.

-0,01

dB

/°

C

Microphone

Temperature

Range:

-

50

to +

60

°C

Microphone

Long

Term

Stability

:

1 dB/

300

years

at

operating

tempera

-

ture

27

°

C.

At

1

00

°

C,

typically

1 dB

per

100

hours

Polarization

Voltage:

200V

Calibration

:

Internal

square

wave

generator

, approx.

1 kHz,

stability

better

than

± 0,2 dB

Directional

Characteristics:

See

curves

page 7

Microphone

K-factor

Adjustment:

+ 4 dB

to

- 2 dB

Reference

Conditions

for

calibration

valid-

ity

:

Type

of

Sound

Field

: Free

Ref.

Direction

of

Incidence

: P

erpendicu-

lar

to

microphone

diaphragm

Ref.

Sound

Pressure

: 20tJPa

Ref.

Sound

Pressure

Level:

84

dB

Ref.

Frequency:

1 kHz

Ref.

Temperature:

20

°C

Ref.

Measuring

Range

:

80

dB

(90

dB

FSD)

Absolute

accuracy

at

Reference

condi

-

tions

:

±0,7 dB

Effect

of

Humidity:

< 0,5 dB

from

0

to

90

%

RH

provided

no

condensation

occurs

Effect

of

Vibration:

See

curves

Fig.15

and

Fig

16

Effect

of

Sound

Field:

At

least

60

dB

below

sensitivity

of

micro-

phone

4165

Effect

of

Ambient

Pressure:

Approx

.

-0,001

dB

per

mbar

at

1013

mbar

Effect

of

Electrostatic

field:

Negligible

with

microphone

grid

fitted

Effect

of

Electromagnetic

Field

:

80A

/ m

(50Hz)

gives:

<

36

dB(A)

<

38

dB(B)

<

46

dB(C)

<

46

dB(Lin)

Effect

of

Temperature

:

-

10to

50

°

C(14to

122

°

F)

±

0,5dB

Batteries:

3 x 1,

5V.

IEC Type

R20

(B

& K

order

No.

OB

0004)

Battery

Life:

(Continuous

operation)

12

hours

with

standard

batteries

(Varta

Super

Dry

282)

(National

Neo Hi-Top

UM

1NE)

50

hours

with

Alkaline

batteries

(Mallory

MN

1

300)

20

hours

with

rechargeable

NiCd-cells

(B & K

order

No. OB

0008

,

3rqd

.)

(Saft

Voltablock

VR 4D)

(Varta

RS

4)

Recharging

from

Power

Supply

Type

2808

,

Battery

Box

ZG

0073

,

and

Charg-

ing

Adaptor

AO

0043

+ 3

dummy

cells

ZR

0017

Dimensions

:

90

X

120

X

550

mm

(4

X 5 X

21,7

in)

(320

mm

. (

12,7

in)

without

extension

rod)

Weight:

3 kg (6,61b)

Accessories

included:

1/

2"

Condenser

Microphon

e Type 41

65

Flexible

Extension

Rod

UA

0196

Input

Adaptor

JJ

2614

Windscreen

UA

0237

3

Screened

Plugs JP

0006

3

Batteries

OB

0004

1

Screwdriver

OA

0001

1

Screwdriver

OA

0027

Accessories

Available

:

See

survey

page 4

2.

CONTROLS

Protection Grid

----------

-ioi

,IJ

PW

'n

----------Microphone

•~11-

---------

Extension Rod

UA

0196

Output

Attenuator

(Transparent)

Input

Attenuator

(Black)

Adj.

Meter Scale

770180

Fig. 2.

1.

Front

view

of

2203

9

MICROPHONE:

PROTECTION GRID:

EXTENSION ROD

UA

0196:

Half-inch

condenser

Microphone

Type

4165.

Protects

the

diaphragm

of

the

microphone

from

physical

damage.

This

grid

should

not

be

removed,

except

when

the

microphone

is

to

be

fit-

ted

with

a Nose Cone

or

Rain Cover,

or

for

inspection

of

the

dia-

phragm.

DO NOT TOUCH THE

DIAPHRAGM

WITH

ANY

OBJECT.

This

flexible

rod

connects

the

microphone

to

the

sound

level

meter

at

a

sufficient

distance

that

the

influence

of

the

body

of

the

sound

level

meter

and

operator

on

the

sound

field

is

minimized.

This

extension

rod

must

be

used

in

order

for

the

instrument

to

conform

to

precision

stan-

dards.

If

a

Dehumidifier

Type

UA

0308

is used,

it

is placed

between

the

mi-

crophone

and

extension

rod.

When

screwing

the

microphone,

extension

rod,

and

sound

level

meter

together,

only

light

finger

torque

should

be used.

METER SWITCH:

AMPLIFIER ON:

METER SCALE:

10

This

11-position

switch

controls

the

main

functions

of

the

2203,

as

follows:

"On

Pull":

When

the

switch

is

pulled

out,

the

2203

is

turned

on

and

the

AMPLIFIER ON

lamp

will

flash.

Allow

at

least

20

s

for

warm-up

be-

fore

using

the

instrument.

"Batt.":

If

the

meter

needle

deflection

is

below

the

area

marked

"Bat-

tery",

the

batteries

must

be replaced (see

section

3.1 ).

"Fast":

The

five

positions

on

the

left

side

of

the

METER SWITCH

give

the

"Fast"

meter

response. (See

Fig.14

in

Chapter

1

.)

"Slow":

The

five

positions

on

the

right

side

of

the

switch

give

the

"Slow"

meter

response. (See Fig.

14

in

Chapter

1.)

"A",

"B",

"C":

Each

position

selects

one

of

the

standardized

frequency-

weighting

networks.

(See Fig.1

in

Chapter

1.)

"Lin.":

Gives

linear

frequency

response

within

the

limits

of

the

instru-

ment,

see

Chapter

1.

"Ext.

Filter":

Selects

an

external

filter

connected

to

the

EXTERNAL FIL-

TER

sockets. No

meter

needle

deflection

will

be

obtained

in

this

posi-

tion

if

a

filter

is

not

connected.

This

lamp

flashes

when

the

instrument

is

switched

on.

The

upper

scale (black) is

calibrated

from

"-1

O"dB

to

"+

1

0"

dB

for

the

reading

of

sound

level (or

vibration

level).

"0"

dB

on

the

scale

corresponds

to

the

attenuator

setting

indicated

inside

the

red Jines.

Thus,

for

example,

if

the

meter

shows

"-2"

dB and

the

attenuator

setting

is

"70"

dB,

then

the

sound

level is

68

dB.

The

lower

scale (red) is used

for

calibration

of

the

instrument

using

the

microphone

K

factor.

This

K

factor

is

found

on

the

individual

cali-

bration

chart

provided

with

the

microphone.

METER LIGHT SWITCH:

METER

MECHANICAL

ZERO

ADJUSTMENT:

When

checking

the

batteries

(METER SWITCH

in

"Batt."

position),

the

meter

n'

eedle

deflection

must

be

in

the

range

indicated

by

the

red

lines

labelled

"Battery"

on

the

lowest

meter

scale.

The

METER SCALE is

illuminated

when

this

self-releasing

switch

is

pressed

down.

It

only

functions

when

the

instrument

is

switched

on.

The

screw

head

just

below

the

METER SCALE is

adjusted

with

the

in-

strument

turned

off

to

give a

meter

needle

deflection

on

the

"-t:JJ"

mark

on

the

meter

scale.

Since

the

2203

can

measure

sound levels

that

vary

over

a

wide

dynamic

range

(from

26

to

140

dB)

but

the

METER SCALE can

only

display

20

dB

of

this

range

at

a

time,

an

at-

tenuator

system

is

necessary

to

set

the

range

of

the

instrument

so

that

the

sound

level

will

be

within

the

20

dB

indicated

on

the

METER SCALE.

In

order

to

minimize

the

chances

of

an

overload,

and

to

give

the

best possible

signal-to-noise

ratio,

a

dual

attenu-

ator

system

consisting

of

INPUT and OUTPUT ATTENUATORS is used. The

correct

use

of

these

switches

is

described

in

Chapter 3,

Operation.

INPUT ATTENUATOR (black):

OUTPUT ATTENUATOR

(transparent):

ADJ.:

EXTERNAL FILTER IN:

EXTERNAL FILTER OUT:

This

8-position

switch

controls

the

gain

of

the

input

amplifier

in

10

dB

steps, and also selects

the

internal

reference

voltage.

The

range

of

ro-

tation

of

this

switch

is

physically

limited

to

a

position

from

"70"

dB

to

"Ref."

being

adjacent

to

the

black spot.

Maximum

input

gain

is

ob-

tained

in

the

fully

clockwise

position;

and

the

internal

reference

vol-

tage

is

selected

in

the

fully

anticlockwise

position

(provided

the

trans-

parent

OUTPUT ATTENUATOR is

also

set

to

its

fully

clockwise

posi-

tion).

This

7-position

switch

controls

the

gain

of

the

output

amplifier

in

10 dB steps. The range

of

rotation

of

this

switch

is

physically

limited

so

that

the

red

lines

on

the

knob

may

only

be moved

anticlockwise

from

the

black

dot.

Maximum

output

gain

is

obtained

in

the

fully

antic-

lockwise

position,

while

the

minimum

output

gain

(red

lines

by

the

black dot) is

recommended

for

use

whenever

possible.

The

total

gain

setting

depends

on

both

INPUT

and

OUTPUT

ATTEN-

UATOR

positions;

the

measuring

range

corresponding

to

that

gain

setting

is

always

directly

indicated

between

the

red

lines

on

the

knob.

This

screwdriver-operated

potentiometer

just

to

the

left

of

the

ATTENU-

ATOR

switches

is used

for

calibration

the

2203.

It

is

adjustable

from

"-2"

dB

to

"+4"

dB.

Socket

for

connection

to

the

input

of

an

external

filter

(such as Octave

Filter

Set

Type 161 3

or

1

/3

Octave

Filter

Set

Type 1

616).

The

output

impedance

is

<50

but

should

be loaded by

at

least

500

0.

Maximum

output

voltage

is 1,6 V peak.

Accepts

plug

JP

0006

or

cable

AO

0007,

etc

..

Socket

for

connection

to

the

output

of

an

external

filter

to

the

2203.

Input

impedance

is

146

kO/

I

45

pF.

An

input

voltage

of

0,31

6 V

RMS

corresponds

to

a

full-scale

meter

deflection.

Accepts

plug

JP

0006

or

cable

AO

0007,

etc

..

11

AMPLIFIER OUTPUT:

TRIPOD-MOUNTING THREADS:

12

The EXTERNAL FILTER

IN

and OUT sockets

may

be connected

to

a

1

61

3 or a 1

61

6

directly

by

means

of

the

Connections

Bar

JP

0400

supplied

with

each

filter.

This socket provides an AC

output

of

3,1 6 V RMS

at

full-scale

meter

needle deflection. The

maximum

output

voltage is

16

V peak

into

a

load impedance

of

at least 10 kO.

It

may

be used

for

connection

to

a

Level Recorder

or

Tape Recorder. Accepts plug

JP

0006

or

cable

AO

0007,

etc

..

There are

two

tripod-mounting

threads

on

the

rear

of

the

2203.

The

upper thread is

for

mounting

of

the

2203

alone,

while

the

lower

thread is for

mounting

of

the

2203

when

fitted

with

a

filter

set (Type

1

61

3 or 161 6). For

vertical

mounting,

a

thread

is also provided on

the

battery cover on

the

bottom

of

the

2203.

3.

OPERATION

This

Instruction

Manual

describes

the

specific

procedures

necessary

to

correctly

use

the

Precision

Sound

Level

Meter

Type

2203

.

However,

there

are

many

aspects

of

sound

measurement

of

a

more

general

nature

that

are

important

to

consider

in

order

to

get

cor-

rect

reproducible

measurements.

Many

of

these

are

discussed

in

the

accompanying

book-

let,

"Measuring

Sound",

which

should

be considered as

part

of

this

Instruction

Manual.

3.1.

BATTERY

CONSIDERATIONS

The

2203

is

powered

by

three

standard

torch

batteries

(D

cells

or

Type R

20

in

IEC

Publi-

cation

86-2)

.

Access

to

the

batteries

is gained by

unscrewing

the

four

screws

which

hold

the

bottom

cover

of

the

2203.

The

batteries

should

be

inserted

such

that

their

posi-

tive

terminals

point

to

the

front

panel

of

the

instrument,

as

shown

in

Fig.3.1

.

Fig. 3.

1.

Battery

compartment

of

2203

Good-quality

dry

cells

give

an operating

time

of

12

hours,

while

alkaline

cells,

such

as

Mallory

Duracell

MN

1300,

give

50

hours

of

continuous

operation.

Rechargeable

nickel-

cadmium

cells

may

also be used,

giving

an

operating

time

of

20

hours.

These

cells

may

be

recharged

using

the

Power

Supply

Type

2808

with

Battery

Box

ZG

0073

and

Charg-

ing

Adaptor

AQ

0043-

see

the

2808

Instruction

Manual.

13

The

2203

may

also be

powered

directly

from

the

mains

using

Mains

Power

Supply

WB

0004

which

is

inserted

in the

battery

compartment

and

at

the

same

time

serves as a

bot-

tom

cover

for

the

instrument.

If

operated

with

Hearing

Aid

Test

Box Type

421

7

it

may

be

powered

by

Power

Supply

Adaptor

UA

0363

as

described

in

the

4217

Instruction

Manual.

The

batteries

should

be removed

from

the

instrument

if

it

is

not

used

for

a long

time

to

prevent

possible

battery

leakage.

3.2.

GENERAL

CONSIDERATIONS

When

connecting

or

disconnecting

the

microphone,

be

sure

that

the

instrument

power

is

turned

off.

In

dry

weather,

it is

recommended

that

static

electricity

be

discharged

from

your

body

before

fitting

or

removing

microphones.

Only

light

finger

torque

should

be ap-

plied

to

the

microphone

and

extension

rod.

Dust

and

foreign

objects

should

be kept

off

the

diphragm,

which

must

not

be

touched

with

any

object.

If

the

diaphragm

must

be

cleaned,

cotton

wool

should

be used

very

carefully.

When

storing

the

instrument,

dry

and

preferably

warm

conditions

are

recommended.

3.3.

CALIBRATION

FOR

SOUND

MEASUREMENTS

3.

3.1.

General

The

2203

may

be calibrated

in

two

ways:

either

using

an

acoustic

calibrator

(effectively

a

miniature

loudspeaker) placed

over

the

microphone;

or

using

the

built-in

reference

volt-

age in

the

measurement.

The

acoustical

method

has

the

advantage

that

it checks

the

en-

tire

instrument,

including

the

microphone.

When

the

instrument

is

first

received,

it

is a

useful

check

to

calibrate

it

by

both

methods;

these

should

agree to

within

about

0,5

dB.

3.3.2.

Acoustical

Calibration

(External Source)

14

The

Sound

Level

Calibrator

Type

4230

or

Pistonphone

Type

4220

is

recommended.

The

4230

generates

94

dB

(±

0,25

dB)

at

a

frequency

of

1000Hz

while

the

4220

generates

1

24

dB(±

0,2

dB) at a

frequency

of

250Hz.

Calibration

with

Microphone

Type

4165

The

calibration

procedure

when

the

2203

is used

with

the

microphone

with

which

it

is

normally

supplied (Type 41 65) is as

follows:

1.

Using

a

screwdriver,

adjust

the

METER

MECHANICAL

ZERO

ADJUSTMENT

screw

if

necessary

to give a

meter

needle

setting

on

the

"_CXJ"

mark

of

the

METER SCALE

while

the

instrument

is

switched

off.

2.

Attach

the

microphone,

extension

rods,

or

cables and

adaptors

to

be used by

screw-

ing

them

together

finger

tight.

(See Fig.8

of

Chapter

1

for

the

selection

of

accesso-

ries, and Fig.2.1

for

a

view

of

the

standard

assembly.) These

must

be

included

in

the

calibration

since

they

all

affect

the

sensitivity.

3.

Pull

the

METER SWITCH

out

to

turn

the

power

on, and

set

it

to

"Batt."

to

check

the

batteries;

then

set

it

to

"Fast"

and

"C"

or

"Lin.".

(The

instrument

warm-up

time

is

20s

.)

BRUEL & KJAER 2203 User manual

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