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Particle Measurement Unit - MET 6.2

MAHA has developed the new MET 6.2 measurement unit for precise particle measurement in diesel and gasoline engine exhaust. Its high measurement accuracy is a distinguishing feature. The unit is extremely small (about the size of a shoe box) and therefore easy to handle and—most importantly—reliable for use in the workshop. Its price is competitive with traditional exhaust gas measuring equipment.

• Continuous measurement of fine particles in the diesel and gasoline exhaust
• Technically advanced with high stability using laser and microprocessor technology
• Easy and reliable, low cost identification of any irregularities within the engine or particle filter
• The MAHA particle measuring device is the solution when upgrading test programs to include particle measurement

Diesel vehicles are a major producer of fine particulate pollution, which is linked to lung and heart disease. Fortunately, good maintenance can greatly reduce particle emissions, by up to 80% in some cases. Reliable identification of high polluting vehicles and validation of repair effectiveness is essential, but the traditional method of measuring smoke opacity is a poor indication of fine particle levels. The MET 6.2 laser technology can identify particles down to less than 100 nanometres (0.0001 mm). Most newer diesel vehicles are fitted with particle filters. These filters when working correctly reduce particle emission by a factor of twenty, so it is essential that their efficiency can be periodically checked. The MET 6.2 provides this capability.

The chart on the left shows a measurement before and after the particulate trap while driving on road conditions. Both measurements were done with MET 6.2 devices. The chart on the right shows a correlation between AVL Micro Soot instrument and MAHA MET 6.2 PM concentration (source: University of Munich).

MET 6.2 Projects: The Necessity for Advanced Emission Testing

Considering the technological progress of engines and emission reduction technologies in modern vehicles, the current emission testing regulation for in-use vehicles is no longer sufficient. It needs to be adjusted in line with current vehicle technology, to ensure that vehicles with high levels of exhaust emissions are detected in the future. Only emission testing that reliably measures the efficiency of all emission components, especially in modern diesel-powered vehicles fitted with a diesel particulate filter, will have an impact on the environment and health.

The authors of this article, who have significant expertise in emission testing, strongly believe that current emission testing as practiced in Europe has lost its effectiveness. Despite the progress of engine technology, emission limit values were not adapted. As a result, the measurement devices no longer meet the requirements.

The On Board Diagnostics in new vehicles introduces an electronic system capable of self-diagnosing exhaust emission deviations. However meaningful this feature, it is not able to amend the limit values, nor can it introduce an efficient tangible measuring method to test compliance with limit values. Especially for modern diesel-powered vehicles equipped with a diesel particulate filter, a conclusive and meaningful assessment is required, that not only tests but that also documents. This would ensure the efficiency of the emission treatment over the entire period the vehicle is used. In the meantime the required measuring instruments are available. These devices have demonstrated and proven their thoroughness at a field test of Working Group Emission 2010 (VdTÜV, DEKRA, ZDK, ASA Verband) involving more than 1.000 diesel vehicles in garages and recognised control organisations. Their accuracy compared to lab instruments used during engine development, was proven and confirmed by university laboratory tests.

In order to adapt diesel emission testing to the present and future requirements, two steps are necessary:

1. First and foremost, the mandatory emission limit values for vehicles need to be adapted to current vehicle technology conditions, as from EURO II. The socalled emission tag values on each vehicle identification plate, of dieselpowered vehicles can be used as a guideline. These values were established during vehicle type approval and documented for the purpose of periodic vehicle inspections.
2. Afterwards, there should be a gradual renewal of emission testing devices for diesel emissions, by introducing new instruments with alternative measuring methods capable of measuring the particulate mass concentration of vehicles in a precise and reliable manner. This measuring procedure should be compulsory for modern diesel-powered vehicles, with a transition period of 3 years. To this intent, these new devices could already be certified today as an alternative for current measuring instruments and it would facilitate the eventual compulsory exchange. Prior to being allowed to use the new devices, they should be granted qualification approval (PTB-A) from the relevant German National Metrology Institute.

About MAHA

MAHA Maschinenbau Haldenwang GmbH & Co. KG. stands for high-tech in the field of motor vehicle testing and workshop outfitting. MAHA test stands are used throughout the world in the testing of cars, commercial vans, motorcycles and special vehicles of all kinds.

MAHA workshop equipment covers the entire spectrum: from lifts, through service units, to modern emission testing technology. Individual test units can be networked to create universal test lanes making MAHA a competent technology partner for vehicle manufacturers and testing organizations around the globe. In spite of MAHA’s high-tech international profile, we have not forgotten that business is done locally. For this reason, our customers are optimally served on the spot by subsidiaries and dealers in more than 130 countries. In over 35 years of operation, MAHA has become a Global Player in the international vehicle testing business underscoring its strengths of offering individual support and high flexibility. We are committed to continuing this tradition of tailor-made solutions and investment security