ISO is an abbreviation for International Organization for Standardization, and EN refers to European
Norm.It is a non-governmental international organization that provides globally recognized standards.
One of the significant standards released by ISO is EN ISO 4551:2021.
The Purpose of EN ISO 4551:2021
EN ISO 4551:2021 is a technical standard specifically developed for the measurement of noise emitted by machinery
and its assessment. The main objective of this standard is to prescribe procedures and provide guidelines for the
accurate determination of sound power levels produced by different machines in both indoor and outdoor environments.
Key Features of EN ISO 4551:2021
1. Sound Power Level Measurement: The standard outlines specific methods and techniques to measure the sound power
level produced by a machine. These measurements are crucial for assessing noise emissions and ensuring compliance
with relevant regulations.
2. Test Environment Specifications: EN ISO 4551:2021 provides detailed requirements and specifications for test
environments, including ambient noise criteria, background noise measurements, and microphone placements. This ensures
consistent and reliable measurement results across different testing facilities.
3. Data Evaluation and Reporting: The standard defines procedures for evaluating and processing the acquired data,
including statistical calculations and uncertainty estimation. It also specifies the content and format of the final
report, which aids in the accurate comparison of noise emission levels between different machines.
4. Indoor and Outdoor Testing: EN ISO 4551:2021 addresses the challenges related to conducting noise emission tests
in both indoor and outdoor environments. It accounts for factors such as sound reflections, weather conditions, and
other external influences that can affect the measured results.
5. Updated Instrumentation Requirements: The standard incorporates the latest instrumentation requirements and
calibration methods, ensuring that the measurements are conducted using accurate and reliable equipment. It provides
guidelines for selecting appropriate measurement devices and procedures for their verification.
Nina She