IEC 61094-2 : 2.0

Table of Contents

FOREWORD<br>1 Scope<br>2 Normative references<br>3 Terms and definitions<br>4 Reference environmental conditions<br>5 Principles of pressure calibration by reciprocity<br>&nbsp;&nbsp;5.1 General principles<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.1.1 General<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.1.2 General principles using three microphones<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.1.3 General principles using two microphones and an<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;auxiliary sound source<br>&nbsp;&nbsp;5.2 Basic expressions<br>&nbsp;&nbsp;5.3 Insert voltage technique<br>&nbsp;&nbsp;5.4 Evaluation of the acoustic transfer impedance<br>&nbsp;&nbsp;5.5 Heat-conduction correction<br>&nbsp;&nbsp;5.6 Capillary tube correction<br>&nbsp;&nbsp;5.7 Final expressions for the pressure sensitivity<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.7.1 Method using three microphones<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.7.2 Method using two microphones and an auxiliary<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;sound source<br>6 Factors influencing the pressure sensitivity of microphones<br>&nbsp;&nbsp;6.1 General<br>&nbsp;&nbsp;6.2 Polarizing voltage<br>&nbsp;&nbsp;6.3 Ground-shield reference configuration<br>&nbsp;&nbsp;6.4 Pressure distribution over the diaphragm<br>&nbsp;&nbsp;6.5 Dependence on environmental conditions<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.5.1 Static pressure<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.5.2 Temperature<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.5.3 Humidity<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.5.4 Transformation to reference environmental conditions<br>7 Calibration uncertainty components<br>&nbsp;&nbsp;7.1 General<br>&nbsp;&nbsp;7.2 Electrical transfer impedance<br>&nbsp;&nbsp;7.3 Acoustic transfer impedance<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.3.1 General<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.3.2 Coupler properties<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.3.3 Microphone parameters<br>&nbsp;&nbsp;7.4 Imperfection of theory<br>&nbsp;&nbsp;7.5 Uncertainty on pressure sensitivity level<br>Annex A (normative) Heat conduction and viscous losses <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;in a closed cavity<br>Annex B (normative) Acoustic impedance of a capillary tube<br>Annex C (informative) Examples of cylindrical couplers for<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;calibration of microphones<br>Annex D (informative) Environmental influence on the<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;sensitivity of microphones<br>Annex E (informative) Methods for determining microphone<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;parameters<br>Annex F (informative) Physical properties of humid air

Abstract

Applies to laboratory standard microphones meeting the requirements of IEC 61094-1 and other types of condenser microphone having the same mechanical dimensions.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	International Electrotechnical Committee
Pages
ISBN
Committee	TC 29
Supersedes	IEC 60327 : 1ED 71