ISO 6798-2:2020 pdf download

ISO 6798-2:2020 pdf download.Reciprocating internal combustion engines — Measurement of sound power level using sound pressure
1 Scope
This document specifies the survey method, which is the measurement method of the sound power level for reciprocating internal combustion engines. This document applies to all reciprocating internal combustion engines falling within the field of application of ISO 3046-1 and other internal combustion engines where no suitable International Standard exists. NOTE In this document, reciprocating internal combustion engines are referred to as engines unless otherwise explained.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3046-1, Reciprocating internal combustion engines — Performance — Part 1: Declarations of power, fuel and lubricating oil consumptions, and test methods — Additional requirements for engines for general use
ISO 3046-3, Reciprocating internal combustion engines — Performance — Part 3: Test measurements
ISO 6798-1, Reciprocating internal combustion engines — Measurement of sound power level using sound pressure — Part 1: Engineering method
ISO 6926, Acoustics — Requirements for the performance and calibration of reference sound sources used for the determination of sound power levels
IEC 60942, Electroacoustics — Sound calibrators
IEC 61672-1, Electroacoustics — Sound level meters — Part 1:Specifications
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions given in ISO 3046-1, ISO 6798-1 and IEC 61672-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Test environment
4.1 General
The test environment shall be a room or a flat outdoor area which is adequately isolated from background noise and which meets the qualification requirements given in 4.3. Environmental conditions having an adverse effect on the microphones used for the measurements (e.g. wind, impingement of air discharge, high or low temperatures) shall be avoided. The instructions of the manufacturer on the measuring instrumentation regarding adverse environmental conditions shall be followed. Particular care should be exercised to ensure that any plane does not radiate any appreciable sound due to vibrations.
4.2 Criterion for background noise
The time-averaged sound pressure level (abbreviated as sound pressure level in the following text) of the background noise measured and meant (energy average) over the microphone positions shall be at least 3,0 dB, and preferably more than 10,0 dB, below the corresponding uncorrected sound pressure level of the noise source under test when measured in the presence of this background noise.