AS/NZS 4476:1997

1 - AS/NZS 4476:1997 ACOUSTICS-OCTAVE-BAND AND FRACTIONAL-OCTAVE-BAND FILTERS
4 - PREFACE
6 - CONTENTS
7 - 1 Scope
7 - 2 Normative references
8 - 3 Definitions
8 - 3.1 bandpass filter:
8 - 3.2 octave ratio:
8 - 3.3 bandwidth designator:
8 - 3.4 reference frequency:
8 - 3.5 exact midband frequency:
9 - 3.6 nominal midband frequencies:
9 - 3.7 bandedge frequencies:
9 - 3.8 normalized frequency:
9 - 3.9 filter bandwidth:
9 - 3.10 octave-band filter:
10 - 3.11 fractional-octave-band filter:
10 - 3.12 filter attenuation:
10 - 3.13 reference attenuation:
10 - 3.14 relative attenuation:
10 - 3.15 normalized effective bandwidth:
11 - 3.16 normalized reference bandwidth:
11 - 3.17 filter integrated response:
11 - 3.18 reference level range:
11 - 3.19 reference input signal level:
11 - 3.20 level difference:
11 - 3.21 reference level difference:
11 - 3.22 level linearity error:
11 - 3.23 linear operating range:
11 - 3.24 level range control:
11 - 3.25 measurement range:
11 - 3.26 analogue filter:
12 - 3.27 sampled-data filter:
12 - 3.28 digital filter:
12 - 3.29 real-time operation:
12 - 3.30 aliased frequency components:
12 - 3.31 anti-alias filter:
12 - 4 Performance requirements
12 - 4.1 General
12 - 4.2 Nominal midband frequencies
12 - 4.3 Reference attenuation
13 - 4.4 Relative attenuation
15 - 4.5 Filter integrated response
16 - 4.6 Linear operating range
16 - 4.7 Real-time operation
16 - 4.8 Anti-alias filters
16 - 4.9 Summation of output signals
17 - 4.10 Flat frequency response
17 - 4.11 Maximum input signal
17 - 4.12 Terminating impedances
17 - 4.13 Reference environmental conditions
17 - 4.14 Sensitivity to various environments
17 - 4.14.1 Ambient air temperature
17 - 4.14.2 Relative humidity
17 - 4.14.3 Alternating magnetic fields
18 - 4.14.4 Electrostatic discharges
18 - 4.14.5 Radio-frequency electromagnetic fields
18 - 4.15 Power supply check
18 - 5 Test methods
18 - 5.1 General
18 - 5.2 Test instruments
19 - 5.3 Relative attenuation
20 - 5.4 Filter integrated response
20 - 5.5 Linear operating range
21 - 5.6 Real-time operation
22 - 5.7 Anti-alias filters
22 - 5.8 Summation of output signals
23 - 5.9 Flat frequency response
23 - 5.10 Sensitivity to variations of the environment
23 - 5.11 Sensitivity to electrostatic discharge
24 - 5.12 Sensitivity to radio-frequency electromagnetic fields
24 - 6 Instrument marking
24 - 7 Instruction manual
26 - Annex A - Midband frequencies
28 - Annex B - Normalized frequencies at breakpoints of limits on minimum and maximum relative attenuation for...
30 - Annex C - Recommendations for verification of the electrical performance characteristics of bandpass filters

Specifies performance requirements and methods for testing the performance of analogue, sampled-data and digital implementations of band-pass filters that comprise a filter set or spectrum analyser. Performance requirements are provided for three filter classes. It is identical with and has been reproduced from IEC 1260:1995.

This International Standard provides performance requirements and methods for testing the performance of analogue, sampled-data, and digital implementations of band-pass filters that comprise a filter set or spectrum analyser. The extent of the passband region of a filter's relative attenuation characteristic is a constant percentage of the midband frequency for all filters of a given bandwidth. An instrument complying with the requirements of this International Standard may contain any number of bandpass filters covering any desired frequency range.Performance requirements are provided for three filter classes designated class 0, class 1, and class 2. Allowed tolerances increase as the class number increases.Bandpass filters complying with the performance requirements of this standard may be part of various measurement systems or may be an integral component of a specific instrument and shall operate in real time. Performance requirements apply to any method that is selected by the manufacturer to implement the design of the filters.Instruments complying with the requirements of this standard are capable of providing frequency-band-filtered spectral information for a wide variety of signals, for example, time-varying, intermittent, and steady; broadband and discrete frequency; and long and short durations. For applications involving transient signals, different realizations of filters meeting the requirements of this standard may give different results.

First published in Australia as AS Z41-1969.
Withdrawn 1996.
First published in New Zealand as NZS 1499:1965.
AS Z41-1969 and NZS 1499:1965 jointly revised, amalgamated and redesignated AS/NZS 4476:1997.