Machine Noise Testing and the Design of Machinery and Production Lines

Modern industrial automation and industrial machine design require not only efficiency, but also compliance with stringent safety standards. One of the key aspects is machine noise testing, which affects working comfort and operator health. Standards such as EN ISO 11202 play an important role in the CE certification process and in ensuring compliance with legal requirements.

EN ISO 11202 Standard: Key Aspects of Machine Noise Testing

EN ISO 11202, the harmonized version of the international ISO 11202 standard, covers methods for measuring noise emitted by machines and equipment. It is an important document for the industrial automation and industrial machine design sectors, as it defines the rules and procedures for measuring emission sound pressure levels at the workstation and at specified positions.

This standard clearly defines how machine noise testing should be performed to obtain reliable and repeatable results. The measurement methods described in the standard apply to steady, variable, and impulsive noise. These measurements are essential for meeting the requirements of the Machinery Directive 2006/42/EC and obtaining CE marking.

One of the main objectives of EN ISO 11202 is to determine emission sound pressure levels directly at the workstation and at other locations around the machine. For engineers and industrial automation integrators, knowledge of these levels is crucial in design and production process automation. The standard also supports measurement activities by providing detailed guidance on microphone placement, environmental conditions, and measurement techniques.

Preparing for measurement in accordance with EN ISO 11202 includes several key steps. First, all potential noise sources in the working environment must be identified. Next, the measurement locations must be carefully defined so that they reflect the machine’s actual operating conditions. The standard also requires the use of suitable measuring instruments, such as microphones and acoustic calibrators compliant with IEC 61672-1, which must be calibrated regularly, a point that is especially important during a safety audit.

The measurement procedures include accurate sound pressure measurements at various points around the machine under different operating conditions. An important element is also the inclusion of K3A environmental corrections, intended to adjust the measurement results so that they better reflect the actual acoustic conditions in the workplace. Analysis of the measurement results leads to the preparation of a detailed report containing machine noise testing data and recommendations for any corrective actions, which also supports technical documentation of machines under 2023/1230.

EN ISO 11202 is also a key document in the context of adapting machines to essential requirements. It enables manufacturers to carry out a comprehensive acoustic assessment of their products, which is necessary for obtaining CE certification. As a result, machines can be operated safely and the risks associated with excessive noise are minimized.

Understanding and properly applying EN ISO 11202 is essential for companies involved in machine design, industrial robots, and production automation. Implementing these standards helps ensure regulatory compliance, improves operator working conditions, and supports overall efficiency and safety in industrial plants.

When applying EN ISO 11202, it is also worth considering numerical calculations (FEM) and modal analysis at the design stage. FEM calculations help identify potential structural issues that may lead to increased noise. Modal analysis makes it possible to identify and control vibrations, which are one of the main sources of noise in machines. Using these tools makes it possible to design machines in a way that minimizes noise generation, which directly improves working conditions and supports compliance with standards.

EN ISO 11202 provides comprehensive guidance that is essential to ensure machines are safe, efficient, and compliant with international standards. It is a foundation for companies striving for excellence in production process automation and in delivering the highest safety standards in their products.

Machine Noise Testing: Measurement Methodology

Machine noise testing is essential for CE certification of machinery. The measurement methodology includes several stages that must be carried out with due care to ensure accurate and reliable results.

1. Preparation for measurement:
   • Identify all noise sources in the design environment. This includes both machines and auxiliary equipment that may affect noise levels.
   • Define the measurement locations in accordance with EN ISO 11202. This requires precise identification of workstations and other points where noise may be particularly troublesome.
2. Measuring equipment:
   • Use microphones and calibrators compliant with IEC 61672-1. The right measuring instruments are essential for obtaining accurate machine noise testing results.
   • Regular calibration of measuring equipment is critical during a safety audit. Calibration nonconformities can lead to incorrect results and non-compliance with standards.
3. Measurement procedures:
   • Measure sound pressure at the workstation and at other locations in accordance with the standard. This procedure requires precise measurements under different machine operating conditions.
   • Use machine guards and sound-absorbing screens where necessary. These measures can significantly reduce noise levels, which is important for compliance with standards.
4. Analysis of results:
   • Take K3A environmental corrections into account. This correction is necessary to reflect actual operating conditions.
   • Prepare a report with the measurement results and recommendations for adapting machines to essential requirements. The report should include detailed data on noise levels and recommendations for reducing them.

Machine Noise Testing: The Importance of CE Certification

Machine noise testing is an integral part of the CE certification of machinery process. CE marking confirms compliance with the requirements of the Machinery Directive 2006/42/EC and the Machinery Regulation 2023/1230. Carrying out accurate noise measurements and analyzing them is essential to obtain the EC declaration of conformity. This means that the machine is safe to use and does not create an excessive risk to operators’ health.

Risk Analysis According to EN ISO 12100

During the design and automation of production processes, it is necessary to carry out risk analysis according to EN ISO 12100. This process includes:

• Hazard identification: In the context of noise, all potential sources that may contribute to excessive noise at the workstation must be identified.
• Risk assessment: Determine the level of risk associated with noise and its impact on workers’ health. This requires a detailed analysis of noise measurement results and comparison with permissible standards. In practice, this can be supported by risk assessment according to ISO 12100.
• Defining risk reduction measures: Implement technical and organizational solutions aimed at reducing noise levels. These may include design changes as well as the use of machine guards.

Practical Aspects of Implementing Standards

Engineers responsible for machine design must take acoustic standard requirements into account at every stage. This also includes understanding how Regulation 2023/1230/EU and Directive 2006/42/EC affect compliance obligations.

1. Design Optimization:
   • Design machines in a way that minimizes noise generation. This may include the use of sound-absorbing materials, appropriate acoustic insulation, and optimization of drives and mechanisms.
   • Apply harmonized standards to ensure compliance with international acoustic standards.
2. Production Process Control:
   • Monitor and adjust production processes to minimize noise sources. Regular inspections and audits are necessary to maintain compliance with standards.
   • Carry out FAT (Factory Acceptance Test) and SAT (Site Acceptance Test), including machine noise testing at different stages of production.
3. Regular Inspections and Maintenance:
   • Ensure regular machine inspections and maintenance to avoid increased noise caused by component wear. Maintaining machines in good technical condition is essential for keeping them compliant with standards.

Integration of Finite Element Analysis and Modal Analysis

Numerical analysis (FEM) and modal analysis can make a significant contribution to reducing noise in machinery. Modal analysis makes it possible to identify and control vibrations, which are one of the main sources of machine noise.

1. Modal Analysis:
   • Use modal analysis to identify resonance frequencies that may cause excessive vibration and noise.
   • Optimize machine design to reduce vibration, which directly lowers noise levels.
2. Application of FEM Analysis:
   • Structural calculations (FEM) are essential to ensure that the machine structure is sufficiently rigid and does not generate additional noise through uncontrolled vibration.
   • FEM analysis helps identify potential structural issues that may lead to increased noise.

Machine Noise Testing: The Employer’s Role in Noise Control

Machine noise testing does not end at the design and manufacturing stage. In accordance with the Use of Work Equipment Directive, employers are required to check noise levels in the workplace on a regular basis. This process includes:

• Regular safety audits, which may be carried out by external companies offering engineering outsourcing.
• Monitoring and documenting noise levels at different points across the production facility.
• Implementing corrective measures when permissible noise levels are exceeded, such as improving acoustic insulation or using machine guards. As part of this process, employers may also benefit from hazard identification in accordance with ISO 12100.

Summary

Machine noise testing is an essential part of modern industrial machine design and production automation. Meeting acoustic standard requirements not only improves working comfort, but is also crucial for machine safety and obtaining the CE mark. Proper machine design, regular safety audits, and adapting machines to essential requirements are the foundations of effective and safe industrial automation.