I.S. EN 61094-2:1994
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
MEASUREMENT MICROPHONES - PART 2: PRIMARY METHOD FOR PRESSURE CALIBRATION OF LABORATORY STANDARD MICROPHONES BY THE RECIPROCITY TECHNIQUE
Hardcopy , PDF
04-25-2022
English
09-30-1994
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Only cited Standards give presumption of conformance to New Approach Directives/Regulations.
FOREWORD
1 Scope
2 Normative references
3 Definitions
3.1 reciprocal microphone
3.2 phase angle of pressure sensitivity of a
microphone
3.3 electrical transfer impedance
3.4 acoustic transfer impedance
3.5 coupler
4 Reference environmental conditions
5 Principles of pressure calibration by reciprocity
5.1 General principle
5.1.1 General principles using three microphones
5.1.2 General principles using two microphones and an
auxiliary sound source
5.2 Basic expressions
5.3 Insert voltage technique
5.4 Evaluation of the acoustic transfer impedance
5.5 Heat-conduction correction
5.6 Capillary tube correction
5.7 Final expressions for the pressure sensitivity
5.7.1 Method using three microphones
5.7.2 Method using two microphones and an auxiliary
sound source
6 Factors influencing the pressure sensitivity
6.1 General
6.2 Polarizing voltage
6.3 Ground shield reference configuration
6.4 Pressure distribution over the diaphragm
6.5 Dependence on environmental conditions
6.5.1 Static pressure
6.5.2 Temperature of microphone
6.5.3 Humidity
6.5.4 Atmospheric conditions
7 Calibration uncertainty components
7.1 General
7.2 Electrical transfer impedance
7.3 Acoustic transfer impedance
7.3.1 General
7.3.2 Coupler dimensions
7.3.3 Front cavity
7.3.4 Acoustic impedance
7.3.5 Physical quantities
7.3.6 Environmental conditions
7.3.7 Correction factors
7.4 Polarizing voltage
7.5 Uncertainty on pressure sensitivity level
Annexes
A (normative) Heat conduction in a closed cavity
B (normative) Acoustic impedance of a capillary tube
C (informative) Examples of cylindrical couplers for
calibration of microphones
C.1 Plane-wave couplers
C.2 Large-volume couplers
D (informative) Environmental influence on the
sensitivity of microphones
D.1 General
D.2 Dependence on static pressure
D.3 Dependence on temperature
E (informative) Methods for determining microphone parameters
E.1 Front cavity depth
E.2 Front cavity volume and equivalent volume
E.3 Acoustic impedance of the microphone
F (informative) Physical quantities
ZA (normative) Other international publications quoted
in this standard with the references of
the relevant European publications
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