ANSI S1.4 : 1983

0 INTRODUCTION
1 PURPOSE AND SCOPE
   1.1 Purpose
   1.2 Design Goal
   1.3 Scope
   1.4 Limitations
2 DEFINITIONS
   2.1 Sound Pressure Level
   2.2 Exponential-Time-Average Sound Pressure Level
   2.3 Sound Level
   2.4 Maximum Sound Level
   2.5 Peak Sound Level
   2.6 Slow Sound Level
   2.7 Impulse Sound Level
   2.8 Time Constant
   2.9 Crest Factor
   2.10 Indicator Range
   2.11 Primary Indicator Range
   2.12 Calibration Frequency
   2.13 Calibration Sound Pressure Level
   2.14 Calibration Range
   2.15 Calibration Angle of Incidence
   2.16 Relative Response Level
3 GENERAL CHARACTERISTICS
   3.1 General
   3.2 Accuracy
   3.3 Omnidirectional Response
   3.4 Frequency Weighting
   3.5 Time-Averaging Characteristics
   3.6 Tests of Complete Instrument
   3.7 Electrical Test Adaptor
   3.8 Peak Characteristics
   3.9 Battery Check
   3.10 Stability
4 DIRECTIONAL CHARACTERISTICS OF THE MICROPHONE AND
   INSTRUMENT CASE
   4.1 Omnidirectional Response
   4.2 Calibration Angle and Directional Tolerances
5 FREQUENCY-WEIGHTING AND AMPLIFIER CHARACTERISTICS
   5.1 Frequency-Weighting Characteristics and Tolerances
   5.2 Weighting Networks
   5.3 Level-Range-Control Tolerance Limits
   5.4 Level Range Overlap
   5.5 Crest Factor
   5.6 Internal Noise
   5.7 Signal Distortion
   5.8 Overload Minimization
   5.9 Nonlinear Distortion
6 EXPONENTIAL-TIME-AVERAGING CHARACTERISTICS
   6.1 Exponential-Time-Average Sound Level
   6.2 Fast and Slow Exponential-Time-Averaging
        Characteristics
   6.3 Impulse Exponential-Time-Averaging Characteristics
   6.4 Steady State Response
   6.5 Peak Characteristic
   6.6 Indicator Range
   6.7 Analog Indicator Scale
   6.8 Digital Indicator
   6.9 Linearity
   6.10 Differential Level Linearity
7 SENSITIVITY TO VARIOUS ENVIRONMENTS
   7.1 Atmospheric Pressure
   7.2 Intense Sound Fields
   7.3 Vibration
   7.4 Magnetic and Electrostatic Fields
   7.5 Air Temperature
   7.6 Humidity
8 TESTS TO VERIFY THE BASIC CHARACTERISTICS OF THE SOUND
   LEVEL METER
   8.1 General
   8.2 Calibration of Entire Instrument
   8.3 Amplifier
   8.4 Time-Averaging Characteristics
9 PROVISIONS FOR USE WITH AUXILIARY EQUIPMENT
   9.1 Corrections for Accessories
   9.2 Output Impedance
   9.3 External Filters
10 NAMEPLATE DATA AND INSTRUCTION MANUAL
   10.1 Nameplate Data
   10.2 Instruction Manual Information
11 REFERENCES TO RELATED ANSI STANDARDS
12 REFERENCES TO RELATED INTERNATIONAL STANDARDS
APPENDIX A: EXPECTED TOTAL ALLOWABLE ERROR IN A MEASUREMENT
            OF CONTINUOUS SOUND AS A RESULT OF ALLOWABLE
            TOLERANCES ON SOUND LEVEL METER CHARACTERISTICS
APPENDIX B: APPROXIMATION OF THE RANDOM-INCIDENCE RELATIVE
            RESPONSE LEVEL
APPENDIX C: RELATIVE RESPONSE OF FREQUENCY WEIGHTING
            CHARACTERISTIC
APPENDIX D: THEORETICAL RESPONSE TO TONE BURSTS
APPENDIX E: TESTS OF ROOT MEAN SQUARE CHARACTERISTICS
FIGURES
TABLES

Defines the minimum requirements for 3 basic types of sound level meters, types 0, 1 and 2, along with performance requirements that become progressively less stringent, proceeding from type 0 to type 2. Each type requires three frequency weightings, A, B and C; and two exponential-time-averaging characteristics, fast and slow.