Specification for frequency weighting for the measurement of aircraft noise (D-weighting)What is BS 5721 Frequency weighting for aircraft noise measurement about? A special frequency weighting has been found useful for certain measurements of aircraft noise. BS 5721 has been specially prepared for use in conjunction with ISO standards on aircraft noise measurements. BS 5721 defines a weighting characteristic which is designated D for the above mentioned purpose. Who is BS 5721 Frequency weighting for aircraft noise measurement for? BS

Spring washers are nowadays manufactured in a variety of materials and although recommendations about the more commonly used spring steels and copper alloys have been included in this standard

Assessment of risk components for a structure

adequate warning of residual hazards and the potential for misuse are given in the training and operating instructions and local to the equipment concerned (see BS EN 12953-7 and BS EN 12953-8)

Sealed access fittings

where the rated voltage is not more than 250 V

Note: Periodic inspection and testing for arc welding equipment are covered in IEC 60974-4

It covers weathertightness

ISO 4141‑3 on construction

ISBN 0 580 44976 9

documentation and marking/identification

medical applications or environments

Pressure vessels for general purposes