NF EN 61183 : 1994

1 Scope
2 Normative references
3 Definitions
4 Calibration method based on free-field measurements
5 Calibration method based on diffuse-field
    measurements
Annexes
A (Informative) Practical calibration method based on
    free-field measurements
B (Informative) Pra?ctical calibration method based on
    diffuse-field measurements
ZA (Normative) Other international publications quoted
    in this standard with the references of the relevant
    European publications
Tables
A.1 Adjustment factors K(0) for calculation of random-
    incidence sensitivity level
B.1 Characteristics of a type LS2aP/LS2F microphone
Figures
1 Reference coordinate system for random-incidence
    sensitivity level calibration based on free-field
    measurements
2 Reference coordinate system for the purpose of
    practical measurement of random-incidence sensitivity
    level based on free-field measurements
A.1 A sound level meter located with its microphone at
    the centre of a sphere and a reference direction for
    sound incidence aligned with the X-axis
A.2 A sound level meter under test mounted on a turntable
    to obtain incidence of sound from different directions
    in the X-y plane
A.3 Method of simulating rotation in the X-Z plane by 90
    degrees rotation of the sound level meter under test
    around an axis coincident with the reference
    direction, and then rotation around a circle in the
    X-Y plane as in figure A.2

Describes a free-field calibration method for determining random-incidence sensitivity levels of sound level meters.