ET Checks Out the New Opsis ‘Real Driving Emissions’ (RDE) On-Vehicle Testing System

ET’s Mike Webley was in rural Sweden recently conducting vehicle road testing. Has Mike got a new test driving job at Volvo or was he doing the infamous Swedish ‘moose-test’?

No, it turns out he was there to have a hands-on demonstration of the new Opsis RDE (Real Driving Emissions) system.

In the short space of time since the VW ‘Dieselgate’ story broke in late 2015, air quality and vehicle emissions has rocketed up the public and political agenda, placing growing pressure on motor manufacturers to clean up their act, from both an emissions and transparency perspective. It has also led to bold moves from several countries including France and the UK stating that sales of new petrol and diesel cars will be banned from 2040.

And crucially, between now and then, new regulations and legislation has come into force to ensure motor manufacturers can no longer ‘cheat the system’ by making it mandatory for the emissions of new vehicles to be tested in real-life, on the road, rather than just in controlled conditions in the laboratory.

From 1st September 2017, every new car model destined for the UK will need to undergo two new emissions tests. The first called the Worldwide Harmonised Light Vehicle Test (WLTP) is a far more stringent lab test and more interestingly, and perhaps more importantly, the second is brand new Real Driving Emissions (RDE) test whereby portable emissions monitoring equipment (PEMS) must be fitted cars and emissions including NOx and particulates must be tested over a variety of speeds, roads, conditions and weather.

Only if vehicles pass both the WLTP and the RDE test will they then be eligible for sale in the UK.

Coming back to our story in Sweden. Opsis AB is one of ET’s longest-standing suppliers who have been at the forefront of fast response, multi-gas monitoring for air quality and stack emissions with their UV and IR DOAS technology for over 30 years. DOAS (differential optical absorption spectroscopy) sounds complex, but is very simple in application and practice and uses three main components; an emitter and receiver linked by fibre optic cable to a rugged spectrometer. Opsis technology can be applied to measure over hundreds of metres for ambient air quality and fenceline monitoring, or over much shorter distance of a few metres or less for monitoring stack emissions. Opsis have already developed systems for measuring exhaust emissions from ships (again legislation driven) and they have now developed a PEMS for testing vehicle emissions in real time (AKA Real Drive Emissions).

The Opsis RDE system is optimised for super-fast on-vehicle exhaust emissions monitoring of CO2, NO and NO2, but can also be configured to measure CO, CH4 and even formaldehyde.

Unlike other PEMS, the Opsis RDE system can be fitted very simply and quickly and Mike was impressed that within 20 minutes, the RDE system was fitted to the test vehicle and he and his Opsis colleague were driving around the rural roads of Furulund making on-board vehicle measurements.

And based on the time-proven, internationally type approved Opsis DOAS technology, there is no need for pumps, heated analysers, condensers, chillers or heated sample lines, making not only the installation fast and simple, but minimising maintenance to the bare minimum.

Traditional analyser based PEMS, due to the complexity of installation and set-up, may realistically only mean that two per day can be tested allowing for installation and the RDE test routine itself, where the Opsis system, taking just 20 minutes or so to install could potentially be used to test at least double the number of vehicles per day, making it a very efficient alternative.