AS IEC 60942-2004

INTRODUCTION1 Scope2 Normative references3 Terms and definitions4 Reference environmental conditions5 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 compatibility6 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 manualAnnex 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 compatibilityAnnex 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 DocumentationAnnex C (normative) - Format for the pattern evaluation report C.0 Introduction C.1 Marking C.2 Submission for test C.3 Pattern evaluation reportBibliography

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.

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 aclass 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 laboratorystandard microphone, as specified in IEC 61094-1, for demonstrations of conformance to therequirements 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, fordemonstrations 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 theinstrument conforms to the requirements of this standard.This standard does not include requirements for equivalent free-field or random-incidencesound pressure levels, such as may be used in the overall sensitivity adjustment of a soundlevel meter.A sound calibrator may provide other functions, for example, tonebursts. Requirements forthese other functions are not included in this standard.

First published as AS IEC 60942-2004.