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The spectroscopic line shape of the CARS intensity therefore resembles a Fano profile which is shifted with respect to the Raman signal. To compare the spectra from multi-component compounds, the (resonant) CARS spectral amplitude should be compared to the Raman spectral intensity. Coherent anti-Stokes Raman spectrum of microscopy oil.
Basically, the HDIUT is an industry agreed to manufacturer run, in-use, on-road testing program. It builds upon the original NTE standard. It is designed to focus on compliance in the real world, and relies on emissions testing, utilizing Portable Emissions Measurement Systems (PEMS) with NOx, HC, CO and PM being the pollutants to be measured. [11]
European emission standards limit the CO 2 emissions of new passenger cars and light vehicles. The European Union average new car CO 2 emissions figure dropped by 5.4% in the year to the first quarter of 2010, down to 145.6 g/km. [36]
An emission spectrum is formed when an excited gas is viewed directly through a spectroscope. Schematic diagram of spontaneous emission. Emission spectroscopy is a spectroscopic technique which examines the wavelengths of photons emitted by atoms or molecules during their transition from an excited state to a lower energy state.
Emission test results from individual vehicles are in many cases compiled to evaluate the emissions performance of various classes of vehicles, the efficacy of the testing program and of various other emission-related regulations (such as changes to fuel formulations) and to model the effects of auto emissions on public health and the environment.
Like all compliance testing, it is important that the test equipment, including the test chamber or site and any software used, be properly calibrated and maintained. Typically, a given run of tests for a particular piece of equipment will require an EMC test plan and a follow-up test report. The full test program may require the production of ...
A CATI PEMS being strapped down inside a vehicle. A portable emissions measurement system (PEMS) is a vehicle emissions testing device that is small and light enough to be carried inside or moved with a motor vehicle that is being driven during testing, rather than on the stationary rollers of a dynamometer that only simulates real-world driving.
From 2014 onwards, software which manipulated air pollution tests was discovered in vehicles from some car makers; the software recognized when the standardized emissions test was being done, and adjusted the engine to emit less during the test. The cars emitted much higher levels of pollution under real-world driving conditions. Some cars ...