New in-field method effectively measures exhaust emissions

Posted 5 December 2014

Engineering researchers at Harper Adams University have developed a new portable testing method to accurately measure the exhaust emissions of agricultural machinery.

Working with Emissions Analytics and supported by CLAAS, postgraduate students have established an effective method that will enable machinery to be tested outside whilst travelling and completing tasks in field.

Traditionally, machines are tested in controlled environments, not taking into account the many variables from real-life scenarios, which result in transient engine loads.

By applying a method recently introduced to the automotive industry, emissions can now be measured on a mobile basis – a first for the UK agricultural sector.

Supervising the project, postgraduate research student, Rob Fillingham, said: “This is the first time that we have measured the exhaust emissions in-field whilst machines are completing real-world tasks.

“To conduct the research, we compared two engine exhaust after treatment systems commonly used by tractors to reduce emissions by testing a CLAAS Axion 830 and CLAAS Arion 650. The Axion is fitted with a SCR (Selective Catalytic Reduction) system whilst the Arion uses EGR (Exhaust Gas Recirculation) combined with a DPF (Diesel Particulate Filter).

“These were then trialled in three conditions – using a dynamometer to add a variable load to the PTO shaft; road testing at high speed with a fully laden trailer; and in field with a subsoiler and power harrow.

“The portable emissions measurement system provided by Emissions Analytics measured levels of Carbon Dioxide, Carbon Monoxide, Nitrogen Oxides and Total Hydrocarbons present, as well as the fuel consumption using the carbon balance method.

“This was then combined with data from the tractor such as GPS position, engine load, PTO speed and forward speed.”

The research took nine months to complete and was undertaken by recent MEng Agricultural Engineering graduate, Miles Metcalfe, for his dissertation project under Rob’s supervision.

By combining the data, Miles and Rob have been able to track the emissions through the field to produce a more accurate and realistic method for testing agricultural machinery.

The research has also enabled Emissions Analytics to see how technology traditionally used to test road vehicles can be applied within a different sector.

Founder and CEO of Emissions Analytics, Nick Malden, said: “For the past three years we have been testing passenger cars and commercial vehicles in real-world conditions to understand their performance, both in terms of their fuel consumption and emissions output.

“Now we have combined our testing expertise with Harper Adams University's technical knowledge to develop a methodology for the agricultural sector.

“As a result of this innovative collaboration we foresee an opportunity for farmers to not only save fuel, but to also reduce damaging emissions by using data gathered from real agricultural practices.”