What is EN ISO 4551:2021

Introduction

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.