AS IEC 60942-2004

Electroacoustics - Sound calibrators

Standards Australia

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INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Reference environmental conditions
5 Requirements
5.1 General
5.2 Sound pressure level
5.3 Frequency
5.4 Influence of static pressure, air temperature
and humidity
5.5 Total distortion
5.6 Power supply requirements
5.7 Specification and calibration of microphones
5.8 Electromagnetic compatibility
6 Instrument marking and documentation
6.1 Marking of the sound calibrator
6.2 Individual calibration chart for a class LS
sound calibrator
6.3 Instruction manual
Annex A (normative) - Pattern evaluation tests
A.0 Introduction
A.1 Submission for test
A.2 Principal values
A.3 Marking of the sound calibrator and supplied
documentation
A.4 Performance tests at and around reference
environmental conditions
A.5 Environmental tests
A.6 Electromagnetic compatibility
Annex B (normative) - Periodic tests
B.0 Introduction
B.1 Submission for test
B.2 Preliminary inspection
B.3 Performance tests
B.4 Calibration of the sound calibrator with other
models of microphone
B.5 Documentation
Annex C (normative) - Format for the pattern evaluation
report
C.0 Introduction
C.1 Marking
C.2 Submission for test
C.3 Pattern evaluation report
Bibliography

Abstract

Specifies the performance requirements for these classes of sound calibrator, laboratory standard (Class LS), Class 1 and Class 2. Identical and reproduced from IEC 60942:2003.

Scope

This International Standard specifies the performance requirements for three classes of sound calibrator: laboratory standard (class LS), class 1 and class 2. Tolerance limits are smallest for class LS and greatest for class 2 instruments. Class LS sound calibrators are normally used only in the laboratory; class 1 and class 2 are considered as sound calibrators for field use.
A class 1 sound calibrator is primarily intended for use with a class 1 sound level meter and a
class 2 sound calibrator primarily with a class 2 sound level meter, as specified in IEC 61672-1.
The tolerance limits for class LS sound calibrators are based on the use of a laboratory
standard microphone, as specified in IEC 61094-1, for demonstrations of conformance to the
requirements of this standard. The tolerance limits for class 1 and class 2 sound calibrators are based on the use of a working standard microphone, as specified in IEC 61094-4, for
demonstrations of conformance to the requirements of this standard.
A multi-level and multi-frequency sound calibrator has the same class designation for all sound pressure level and frequency combinations for which the instruction manual states that the
instrument conforms to the requirements of this standard.
This standard does not include requirements for equivalent free-field or random-incidence
sound pressure levels, such as may be used in the overall sensitivity adjustment of a sound
level meter.
A sound calibrator may provide other functions, for example, tonebursts. Requirements for
these other functions are not included in this standard.