Digital Filters
Weighting filters
A meeting requirements of IEC 61672-1:2013 for the Class 1 “A” filters
C meeting requirements of IEC 61672-1:2013 for the Class 1 “C” filters
Z meeting requirements of IEC 61672-1:2013 for the Class 1 “Z“ filters
B meeting IEC651 for the Class 1 filters
See Chapter C.3 for the A, C, B and Z filters characteristics.
Noise levels (measured with SV 18A preamplifier, equivalent impedance ST 03 and 50 Ω BNC terminal,
Microphone compensation switched off).
Range Low
A weighting < 3.0 µV
RMS
B weighting < 3.0 µV
RMS
C weighting < 3.0 µV
RMS
Z weighting < 4.5 µV
RMS
.
Range Normal
A weighting < 12.0 µV
RMS
B weighting < 12.0 µV
RMS
C weighting < 12.0 µV
RMS
.
Z weighting < 16.0 µV
RMS
C.2.2 1/1 and 1/3 octave filters
1/1 Octave filters 11 filters with centre frequencies from 16.0 Hz to 16 kHz (base 10), meeting
IEC 61260-1:2014 standard for Class 1
16.0 kHz 1/1 Octave filter (Audio/Full band)