Describes instruments for the measurement of frequency weighted and time averaged sound-pressure levels. Ensures specified accuracy and stability of an integrating sound level meter and reduces to the practical minimum any differences in equivalent measurements taken with instruments of various makes and models which satisfy the requirements of this standard. Specifies the following characteristics and test methods for integrating sound-level meters:
a)integrating and averaging characteristics;
b)indicator characteristics;
c)overload sensing and indicating characteristics.

IEC 60804:1985

Integrating-averaging sound level meters