《SECRETS OF NOISE CONTROL SECOND EDITIN》

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CONTENTSList of Figures3

List of Tales7

Introduction11

Chapter 1-WHAT IT'S ALL ABOUT1

Chapter 2-GETTING DOWN TO BASICS21

Chapter 3-QUIET,PLEASE!43

Chapter 4-WILL SOMEONE PLEASE FIND THAT NOISE SOURCE!75

Chapter 5-SOUND OUTDOORS111

Chapter 6-SOUND INDOORS143

Chapter 7-THE SILENCERS175

Chapter 8-MEASURE UP209

Chapter 9-THE MANAGEMENT OF NOISE CONTROL231

References251

Index255

LIST OF FIGURES1 SCHEDULE OF NOISE CONTROL ACTIVITIES FOR PLANT DESIGN6

2 PLOT PLAN OF AJAX PLANT18

3 TWO SOUND SPECTRA WITH THE SAME DBA LEVELS37

4 OCTAVE BAND SOUND PRESSURE LEVELS OF CUTTER EQUIPMENT MEASURED IN TEST ROOM 5'FROM UNIT, WITHOUT SILENCER40

5 OCTAVE BAND SOUND PRESSURE LEVELS OF CUTTER EQUIPMENT MEASURED IN TEST ROOM 5'FROM UNIT, WITH SILENCER40

6 PERCENTAGE OF POPULATION WITH HEARING LOSS(OR HEARING LEVEL,HL)OF 26 DB OR GREATER WHEN AVERAGED AT 500,1000,2000 HZ AS A FUNCTION OF STEADY NOISE LEVEL,8 HOURS PER WORKDAY,IN DBA50

7 NC CURVES52

8 PNC CURVES53

9 GRAPHIC PRESENTATION OF A COMMUNITY NOISE SURVEY62

10 NOISE RATING CURVES FOR OCTAVE BAND SOUND PRESSURE LEVELS63

11 BOILER HOUSE EQUIPMENT LAYOUT71

12 FAN NOISE SOURCES78

13 FAN TYPES:(A)VANEAXIAL;(B)BACKWARD CURVED BLADE;(C)TUBEAXIAL;(D)RADIAL;(E)RADIAL TIP BLADE;(F)AIRFOIL BLADE79

14 SOUND PRESSURE LEVELS 100 FEET FROM ENDS OF TYPICAL PROPELLER FAN,CNETRIFUGAL FAN,AND EJECTOR TOWERS84

15 MOTOR/GEAR/PUMP SYSTEM90

16 RANGE OF A-WEIGHTED SOUND LEVELS FOR LARGE COM-PRESSORS(4000-12000 RPM)92

17 GENERALIZED OCTAVE BAND SOUND PRESSURE LEVELS FOR CHILLERS93

18 BASE SOUND PRESSURE LEVEL FOR CONTROL VALVES96

19 CORRECTION FACTOR FOR GAS(OR STEAM)SIZING COEFFICIENT TO BE USED IN VALVE NOISE PREDIC-TION96

20 CORRECTION FACTOR FOR VALVE PRESSURE DROP RATIO97

21 BASE SOUND PRESSURE LEVEL AT 10′ FROM AN AIR VENT99

22 VENT SOUND PRESSURE LEVEL GRAPHS100

23　 DIRECTIVITY FACTORS FOR VARIOUS SOUND RADIA-TING PATTERNS114

24 FREE FIELD SOUND PRESSURE LEVELS117

25 APPROXIMATE CORRECTION FOR AIR ATTENUATION120

26 ONE THIRD OCTAVE BAND TO OCTAVE BAND SOUND TRANSMISSION LOSS CONVERSION123

27 GENERALIZED SOUND TRANSMISSION LOSS CURVE124

28 EFFECT ON TRANSMISSION LOSS OF OPENINGS IN A BARRIER130

29 SOUND ABSORPTION COEFFICIENTS FOR VARIOUS THICKNESSES OF GLASS FIBER147

30 EFFECT OF DISTANCE AND ROOM CONSTANT ON SOUND PRESSURE LEVELS WITHIN A ROOM FOR Q＝1148

31 FAN ARRANGEMENT AND DUCT LAYOUT156

32 OPERATOR LOCATION IN ROOM159

33 　FAN LAYOUT171

34 　TWO TYPES OF SILENCERS:(A)ABSORPTIVE SILEN-CER FOR PRESSURE REDUCTION REGULATOR,AND(B)REACTIVE AND ABSORPTIVE SILENCER USED FOR STEAM AND PROCESS VENTS180

35 BARRIER ATTENUATION188

36 FAN PLENUM191

37 CLASSIFICATION OF VIBRATION ISOLATORS194

38 　TRANSMISSIBILITY FOR VARIOUS DAMPING FACTORS195

39 STATIC DEFLECTION CURVE FOR A SPRING ISOLATOR197

40 　TWO CONFIGURATIONS FOR VIBRATION DAMPING:(A)SURFACE OR FREE LAYER DAMPING,AND(B)CON-STRAINED LAYER DAMPING201

41 RELATIVE DAMPING AS A FUNCTION OF RELATIVE THICKNESS AND RELATIVE YOUNG'S MODULUS FOR A HOMOGENEOUS DAMPING LAYER202

42 VENT SILENCER ATTENUATION204

43 FREQUENCY CHARACTERISTICS OF THE A,B,AND C SCALE WEIGHTING NETWORKS212

44 SOUND LEVEL METERS212

45 BANDWIDTH VS FREQUENCY FOR CONSTANT PERCENT-AGE AND CONSTANT FREQUENCY FILTERS219

46 COMPARISON OF ACOUSTICAL DATA SAMPLE ANA-LYZED WITH OCTAVE BAND,ONE THIRD OCTAVE BAND,AND NARROW BAND FILTERS220

47 COMMUNITY NOISE SAMPLE SHOWING ANALYZER SAM-PLING INTERVAL AND CORRESPONDING INTERVAL SOUND PRESSURE LEVELS222

48 BLOCK DIAGRAM OF INSTRUMENTATION SYSTEM FOR STATISTICAL ANALYSIS OF ENVIRONMENTAL NOISE223

49 AUDIOMETRIC TESTING OPERATION SHOWING SOUND ISOLATION BOOTH AND AUDIOMETER228

50 MOBILE AUDIOMETRIC TESTING UNIT229

LIST OF TABLESⅠ ACTIVITIES OF THE NOISE CONTROL CONSULTANT4

Ⅱ ESTIMATING THE SCOPE OF NOISE CONTROL ACTIVITIES8

Ⅲ MANUFACTURERS OF ACOUSTICAL AND VIBRATION PRODUCTS10

Ⅳ　TWO PLACE LOGARITHMS24

Ⅴ ADDITION OF DECIBELS30

Ⅵ STANDARD OCTAVE BANDS32

Ⅶ OLD OCTAVE BANDS33

Ⅷ CONVERSION OF OLD OCTAVE BAND LEVELS TO NEW OCTAVE BAND LEVELS33

Ⅸ VIBRATION DEFINITIONS(FROM ISO STANDARD)35

Ⅹ CONVERSION TO"A"SCALE READINGS36

Ⅺ OSHA PERMISSIBLE NOISE EXPOSURE46

Ⅻ ACCEPTABLE NC LEVELS FOR VARIOUS ACTIVITIES52

ⅫⅠ SPEECH INTERFERENCE LEVELS FOR TELEPHONE COMMUNICATIONS54

ⅩⅣ SPEECH INTERFERENCE LEVELS FOR FACE-TO-FACE COMMUNICATION54

ⅩⅤ EXTERIOR AND INTERIOR NOISE EXPOSURE STAN-DARDS-DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT56

ⅩⅥ FEDERAL HIGHWAY ADMINISTRATION NOISE STAN-DARDS-DESIGN NOISE LEVELS AND LAND USE RELATIONSHIPS59

ⅩⅦ CONSTRUCTION NOISE REQUIREMENTS:GENERAL SERVICES ADMINISTRATION60

ⅩⅧ CORRECTION FACTORS FOR COMMUNITY NOISE64

ⅩⅨ COMMUNITY REACTION TO NOISE64

ⅩⅩ CORRECTIONS TO THE MEASURED SOUND LEVEL IN DBA67

ⅩⅩⅠ CORRECTIONS TO BASIC CRITERION FOR DIFFERENT TIMES OF DAY68

ⅩⅩⅡ CORRECTIONS TO BASIC CRITERION FOR RESIDEN-TIAL PREMISES IN DIFFERENT ZONES68

ⅩⅩⅢ ESTIMATED COMMUNITY RESPONSE TO NOISE69

ⅩⅩⅣ BASIC SOUND POWER LEVELS OF FANS81

ⅩⅩⅤ SOUND LEVELS OF VARIOUS PUMP TYPES85

ⅩⅩⅥ TYPICAL SOUND POWER LEVELS FOR AN 1800 RPM CENTRIFUGAL PUMP86

ⅩⅩⅦ A-WEIGHTED MOTOR SOUND POWER LEVELS87

ⅩⅩⅧ APPROXIMATE CONVERSION FACTORS FROM OCTAVE BAND TO DBA SOUND POWER LEVELS FOR MOTORS86

ⅩⅩⅨ LARGE HP MOTOR SOUND POWER LEVELS88

ⅩⅩⅩ SOUND POWER LEVELS OF GEARS89

ⅩⅩⅩⅠ OCTAVE BAND SOUND POWER LEVELS OF AN 800 HP CENTRIFUGAL COMPRESSOR91

ⅩⅩⅩⅡ A-WEIGHTED SOUND LEVELS OF DRY TYPE TRANS-FORMERS AT 1′94

ⅩⅩⅩⅢ OCTAVE BAND CORRECTION FACTORS FOR NEMA(DBA)SOUND RATINGS94

ⅩⅩⅩⅣ CORRECTION FACTORS FOR PIPE WALL ATTENUATION97

ⅩⅩⅩⅤ VENT NOISE CORRECTION FACTORS FOR GAS SPECI-FIC GRAVITY101

ⅩⅩⅩⅥ OCTAVE BAND SOUND PRESSURE LEVEL CORRECTION FACTORS FOR A VENT101

ⅩⅩⅩⅦ　 DIRECTIVITY OF A VERTICAL STACK121

ⅩⅩⅩⅧ 　CONSTANT FOR EQUATION 32125

ⅩⅩⅩⅨ SURFACE DENSITY AND PLATEAU HEIGHT VALUES FOR VARIOUS MATERIALS125

ⅩⅩⅩⅩ INCREASE IN TL FROM DOUBLE WALL CONSTRUCTION127

ⅩⅩⅩⅩⅠ SOUND TRANSMISSION LOSS FOR 1/4″ DOUBLE GLASS WITH 1/2″ AIR SEPARATION127

ⅩⅩⅩⅩⅡ SOUND ABSORPTION COEFFICIENTS OF GENERAL BUILDING MATERIALS AND FURNISHINGS146

ⅩⅩⅩⅩⅢ ATTENUATION IN BARE RECTANGULAR METAL DUCTS154

ⅩⅩⅩⅩⅣ EFFECT OF REFLECTION AT OPEN END OF DUCT155

ⅩⅩⅩⅩⅤ APPROXIMATE ATTENUATION OF ELBOWS155

ⅩⅩⅩⅩⅥ SOUND POWER LEVELS AT AIR OUTLETS157

ⅩⅩⅩⅩⅦ SOUND POWER PRODUCED BY TURNING VANES162

ⅩⅩⅩⅩⅧ 　AIR VELOCITY CORRECTION FACTORS FOR TURNING VANE SOUND POWER162

ⅩⅩⅩⅩⅨ 　TRANSMISSION LOSS OF VARIOUS GAUGES OF STEEL164

L ATTENUATION OF ELBOWS WITH ACOUSTICAL LININGS FOR SQUARE DUCTS192

LⅠ ISOLATOR DAMPING FACTORS196

LⅡ MATERIAL LOSS FACTORS201

LⅢ MEASUREMENT STANDARDS FOR INDUSTRIAL EQUIP-MENT NOISE214

LⅣ CORRECTION FACTORS FOR BACKGROUND NOISE215

LⅤ VALUES OF K FOR ANALYZERS216

LⅥ FACTOR"a"FOR CALCULATING % CONFIDENCE LIMITS225

LⅦ PERIODICALS ON ACOUSTICS234

LⅧ RECOGNIZED ACOUSTICAL STANDARDS240