800-680-1220 / +1 651-490-2860 (US) All locations

TSI.com (0)

Research and Development

|

Software

Service

Contact

TSI.com
(0)

Menu

Transport, Tools and Research

Brake and Tire Wear Testing

Brake and tire wear emissions are significant contributors to air pollution, especially in urban areas with heavy traffic. As exhaust emission regulations tighten, attention has shifted to understanding and mitigating non-exhaust emissions from everyday driving. These emissions consist mainly of fine particles released from the friction of braking and tire wear on road surfaces.

Testing for these emissions involves advanced measurement techniques to capture a wide range of particle sizes and concentrations. This testing is essential for assessing the impact of brake and tire wear on air quality and public health. By utilizing sophisticated instrumentation, researchers can evaluate how factors like driving conditions and material compositions affect particle generation, aiding manufacturers in improving designs to reduce environmental impact.

As concerns about particulate matter continue to grow, accurate emissions testing is becoming increasingly important. Understanding brake and tire wear emissions can inform regulations and guide industry practices, contributing to cleaner air and healthier communities.

Importance of Non-Exhaust Emissions

Non-exhaust emissions account for nearly half of road transport emissions contributing to air pollution (Alemani et al., 2015). As stricter regulations reduce exhaust emissions, particles from disc brakes are gaining attention (Bukowiecki et al., 2009). Factors like speed, temperature, and pressure during braking can rapidly change, affecting the size and rate of particles released. This highlights the need for reliable measurement systems. As the significance of non-exhaust emissions increases, discussions about new regulations are emerging (Grigoratos et al., 2015). Brake pad manufacturers continuously test their products to enhance performance and comply with global standards set by the UN ECE Particle Measurement Programme.

Brake Wear Emissions

Measuring brake wear emissions is a complex task that requires sophisticated systems capable of detecting a wide range of particle sizes and concentrations. As brakes are used, particles are emitted rapidly, and these emissions can exhibit both unimodal and bimodal size distributions, particularly when larger particles over 1 μm are present. Advanced particle measurement systems are essential for capturing the full spectrum of emissions during braking events. By providing data on particle number size distributions, these systems can inform future regulations and help manufacturers improve brake materials. Accurate measurement is crucial, as it directly impacts our understanding of brake wear contributions to air pollution.

Tire Wear Emissions

Tire wear emissions also play a significant role in non-exhaust pollution, with studies estimating that they account for over half of small particle pollution from road transport. The composition of tire wear particles is still being explored, as they often contain a mix of materials from tires, road surfaces, and other debris. Factors such as road conditions, driving styles, and external emissions influence tire wear rates and, consequently, the amount of particulate matter released into the environment. Research indicates that while ultrafine particles may not always be emitted under normal driving conditions, they can be present during steady-state testing. Understanding these emissions and their potential health effects is critical, highlighting the need for further research to assess their impact on public health and environmental safety.

Measurement Methods

Particle Number Concentration

Measuring particle number concentration is crucial for understanding brake and tire wear emissions, particularly as regulations around non-exhaust emissions tighten. The total number concentration of particles generated during braking events can be evaluated using advanced instrumentation, such as the Engine Exhaust Particle Sizer™ (EEPS™) and the Water-based Condensation Particle Counter (WCPC). The EEPS™ effectively measures particles from 5.6 nm to 560 nm, while the N-WCPC provides rapid and accurate readings, making them ideal for capturing the fast changes in particle concentration that occur during braking.

Frequently asked questions

Q. What is brake and tire wear testing?

This testing measures particles and emissions from brake and tire wear to understand environmental impact and inform cleaner technology development.

Q. Why is brake and tire wear testing important?

It identifies particulate matter emissions, which contribute to air pollution, helping develop sustainable transport practices and meeting air quality standards.

Q. What techniques are used for testing?

Real-time particle counters, spectrometers, and chemical analysis tools like TSI’s aerosol and particle sizers are commonly used to measure and characterize wear particles.

Q. What are the main sources of brake and tire wear particles?

Braking friction, tire-road contact, and acceleration produce particles, releasing metals, rubber, and other materials into the air.

Q. Are there any regulations regarding non-exhaust emissions?

Regulatory frameworks regarding non-exhaust emissions are evolving. While traditional regulations have focused on exhaust emissions, there is growing recognition of the need to address non-exhaust sources. Governments and regulatory bodies are increasingly looking at strategies to include brake and tire wear emissions in their air quality standards. Find out more about the regulations in place - click here

Q. How are tests performed on brakes and tires?

Tests can be done on-road or in controlled lab settings, where specialized equipment measures particle size, concentration, and chemical composition.

Regulations Addressing Non-Exhaust Emissions

Regulations Addressing Non-Exhaust Emissions

Regulations on non-exhaust emissions are evolving globally, with bodies like the EU, UNECE, and CARB recognizing and addressing brake and tire wear in air quality standards.

Read More