top of page

Dekati Ltd. is a world leader in designing and manufacturing innovative fine particle measurement solutions. We have over 25 years of experience in providing measurement instruments and complete measurement solutions to a wide variety of environments and sample conditions. We take pride in the quality and robustness of our products and are committed to finding the best possible solution for your aerosol measurement needs. Our experience and expertise in aerosol measurement applications is at your disposal throughout the lifecycle of your investment via our global partner network. All Dekati® Products are developed and manufactured in Finland and are available with up to five-year warranty.

Our brake emission measurement solutions include both particle detection and dilution systems, and today we have solutions for both for research and routine monitoring of brake emissions from 6 nm up to 10 µm. The highlights of our product line include the ELPI®+ product family that enables real-time measurement of particle size distribution in up to 500 size channels 6 nm-10 µm. ELPI®+ products also always include the option for post-measurement chemical analysis of the size classified, collected samples. The High Temperature version of the ELPI®+ additionally allows direct measurement of up to 180 °C aerosol sample without the need to cool the sample. In addition to the ELPI®+ instruments, Dekati® Product Line includes several other instruments for both particle detection and aerosol sample conditioning and dilution. Visit us in the exhibition area to learn more about Dekati® Measurement Solutions for brake wear emission measurements!

SEE MORE

Representative

SEE MORE

Stay up to date with FISITA Spotlight

More Blogs Item Title

Excerpt from the blog goes here - this will give the reader a brief snapshot of what the post is about...

16 July 2021

READ NOW

See FISITA Library items from Dekati

EB2022-FBR-013

Oral

University of Leeds: Mr. Ishmaeel Ghouri, Prof. David Barton

Detail

The automotive industry continually strives to increase efficiency and reduce emissions through a variety of methods. Such approaches typically involve attaining technological advancements in engine performance, enhancing aerodynamic efficiency, or reducing vehicle weight [1]. Despite numerous effects, one area that appears to be largely overlooked is the effect of the brake system on environmental emission. A key by-product of the braking mechanism is the emission of particles from the brakes into the environment. These particles not only cause pollution but also pose possible risks to human health [2]. No current legislation exists in terms of limiting the quantity or type of brake emissions produced, despite there being stringent legislation in place with regards to exhaust emission [3]. It is speculated that friction brakes will become one of the dominant sources of particulate emissions because of the rising number of electric vehicles on the road each year [4]. Electric vehicles still require friction brakes to supplement regenerative braking and it is likely that these will continue to use the traditional grey cast iron brake rotor, which is both heavy and exhibits poor corrosion resistance, and is therefore likely to contribute significantly to brake wear emissions. In order to understand the inter-relation between brake rotor corrosion and particulate emission, this study concentrates on quantifying such emissions from a conventional grey cast iron friction brake both before and after exposure to a corrosive environment. The ‘drag braking’ duty cycle was chosen for this study, as this produces near steady-state conditions at the friction interface. Test were at a constant speed of 150 rpm at three different brake hydraulic pressures, 5 10 and 15 bars. As for the brake pad material, OEM-recommended brake pad materials are used. The duration of each test was 90 minutes, and each test was repeated three times. Tests were conducted within an enclosed chamber on the Leeds brake dynamometer and airborne emissions were sampled using a Dekati electrical low-pressure cascade impactor (ELPI+). After the three repeated test cycles have been completed, the brake wear particles captured by the ELPI+ were examined as described below. The corrosion test consisted of exposing the brake rotor to a corrosive environment in a salt spray chamber. The salt spray conditions were based on the ASTM B117-11 standard, under 96 hours of exposure. The corroded brake disc then underwent the drag brake duty cycles which as before were repeated three times for each pressure condition. Similarly, to the non-corroded tests, the brake wear particles were collected from the ELPI+ and later examined. The post-test analysis consisted of using different microscopy techniques to investigate the topography and composition of the brake wear particles. Gravimetric wear measurement methods were incorporated into the post-test protocol. Advanced characterisation techniques such as energy-dispersive X-ray spectroscopy (EDX) and secondary electron microscope (SEM) were used to characterise the surfaces of the brake pads and to characterise and identify the elements of the brake wear particles collected from the ELPI+ before and after the corrosion cycles. References [1] “Vehicle Efficiency | EESI.” [Online]. Available: https://www.eesi.org/topics/vehicle-efficiency/description. [Accessed: 15-Jan-2020]. [2] “‘London throat’: Toxic brake dust could cause condition, scientists say - BBC News,” https://www.bbc.co.uk/news/uk-england-london-51049326. [Online]. Available: https://www.bbc.co.uk/news/uk-england-london-51049326. [Accessed: 25-Jan-2020]. [3] “Pollution warning over car tyre and brake dust - BBC News.” [Online]. Available: https://www.bbc.co.uk/news/business-48944561. [Accessed: 03-Dec-2019]. [4] P. Monks et al., “AIR QUALITY EXPERT GROUP. Non-Exhaust Emissions from Road Traffic,” p. 51014, 2013.

EuroBrake 2022

Environmental impact of brake wear particulate emissions

WATCH VIDEO
DOWNLOAD PDF
DOWNLOAD SLIDES

Downloads

The effects of corrosion on particle emissions from a grey cast iron brake disc, EB2022-FBR-013, EuroBrake 2022

EB2021-STP-020

Paper + Video + Slides

Detail

Mr. Asmawi Sanuddin, University of Leeds, UNITED KINGDOM

Prof. David Barton, University of Leeds, UNITED KINGDOM

Dr. Peter Brooks, University of Leeds, UNITED KINGDOM

Dr. Carl Gilkeson, University of Leeds, UNITED KINGDOM

Dr. Shahriar Kosarieh, University of Leeds, UNITED KINGDOM

Prof. Suman Shrestha, Keronite International Ltd, UNITED KINGDOM


Lightweight disc brake rotors have become a popular alternative to conventional grey cast iron (GCI). The thermal and tribological response of these brake rotors will differ during a braking operation. This may result in the generation of particulate wear debris with different characteristics, which can affect the environment and human health to different degrees. Studies have shown a relationship between adverse health effects and the characteristics of airborne particulate matter such as particle size, concentration and chemical composition. In this study, the particulate matter released from a novel lightweight disc brake rotor is compared to that released from the conventional grey cast iron rotor. The lightweight brake rotor was made of aluminium alloy (Al6082) and its rubbing surfaces were treated using the Plasma Electrolytic Oxidation (PEO) process. The process produced hard, dense, wear-resistant and well-adhered alumina coatings of approximate thickness 50 microns.


A novel test rig was developed based upon the existing Leeds full-scale disc brake dynamometer. An enclosure was constructed around the brake assembly and ducting was carefully designed to ensure the cleanliness of the intake air to the system. Both brake rotors were tested under drag-braking conditions of constant sliding speed and applied braking pressure. Three braking test conditions with hydraulic pressures of 5, 10 and 15 bar at a constant speed of 135 rpm were selected from initial brake dynamometer tests. Braking test parameters of rotor rubbing surface temperature and coefficient of friction were measured during the tests and their effect on the brake wear particle characteristics were investigated. To measure and collect airborne brake wear particles, the Dekati ELPI+ unit was utilised along with a custom-made probe. This probe was made of stainless steel and its geometry was tailored to comply with the isokinetic concept. A scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectroscopy (EDX) system was utilised to investigate the morphology and chemical composition of the airborne brake wear particles collected by the Dekati unit.


The initial comparison results showed that the PEO-treated lightweight aluminium alloy (PEO-Al) rotor has the potential not only to significantly reduce the unsprung mass of the vehicle but also reduce particulate matter emissions compared with the standard GCI rotor. The results also revealed that the percentage of iron contained in the PEO-Al debris was about threefold lower than that from the GCI rotor under all steady-state drag braking conditions studied which may have important health implications.


EuroBrake 2021

ACB

WATCH VIDEO
DOWNLOAD PDF
DOWNLOAD SLIDES

Downloads

Preliminary Comparisons of Particulate Emissions Generated from Different Disc Brake Rotors, EB2021-STP-020, EuroBrake 2021

EB2021-STP-002

Paper + Video + Slides

Detail

Mr. Fabian Limmer, University of Leeds, UNITED KINGDOM

Prof. David Barton, University of Leeds, UNITED KINGDOM

Dr. Carl Gilkeson, University of Leeds, UNITED KINGDOM

Dr. Peter Brooks, University of Leeds, UNITED KINGDOM

Dr. Shahriar Kosarieh, University of Leeds, UNITED KINGDOM


The brake industry is currently on the search for lighter, corrosion-resistant and more eco-friendly brake systems. Apart from health and environmental issues, the main drivers for this development are the changing load profiles arising from the megatrends of electrification and autonomous driving. As the brake disc and brake pad together represent a tribological system, both components must be adjusted in order to achieve optimal functionality.


Testing of brake friction couples, however, is usually a very costly, energy and time-consuming process, that only allows for a very limited range of material concepts to be considered. This is where testing friction materials on a small-scale level has great advantages because much time and money can potentially be saved in sample generation, testing and post-test analysis compared with full-scale testing.


A novel small-scale test bench has been developed at the University of Leeds which aims to screen friction materials under realistic braking conditions. The foundation of the setup is the Bruker UMT TriboLab tribometer operating in a modified pin-on-disc type configuration. Popular full-scale cycles such as the WLTP based real-world driving cycle have been implemented to replicate current everyday driving scenarios as well as custom cycles that aim to simulate possible future load profiles. A full enclosure around the friction couple has been designed using CFD to allow for controlled airflow and subsequent wear debris capture and analysis. The wear particles generated during braking operation are sampled under isokinetic conditions using the well-known Dekati ELPI+ instrument.


The paper will report on the scaling approach used to design the test bench and the conversion of the WLTP based real-world driving cycle to a non-inertial system. Details of the CFD analysis as well as preliminary test results will also be presented.

EuroBrake 2021

BEML

WATCH VIDEO
DOWNLOAD PDF
DOWNLOAD SLIDES

Downloads

Development of a Small-scale Test Bench for Investigating the Tribology and Emission Behaviour of Novel Brake Friction Couples, EB2021-STP-002, EuroBrake 2021
LOAD MORE

No matching results found.

arrow&v
SEARCH
SEARCH
LOAD MORE
arrow&v
arrow&v

Message goes here.

People

bottom of page