Abstract: A method and a measuring system for determining exhaust gas emissions from a moving vehicle by a remote optical measuring technique. The model and/or type of the vehicle under examination is identified, and the driving situation of the vehicle in question is determined at the moment of measurement. A calculatory vehicle model is used to determine a case-specific estimate for the carbon dioxide concentration of the exhaust gas plume depending on the vehicle in question and its driving situation. The accuracy of determining the concentrations of the actual emission gases is improved by eliminating the inaccuracy of the carbon dioxide concentration values.

Abstract: The invention relates to a method and a measuring system for determining exhaust gas emissions from a moving vehicle (20) by a remote optical measuring technique. According to the invention, the model and/or type of the vehicle (20) under examination is identified, and the driving situation of the vehicle (20) in question is determined at the moment of measurement. A calculatory vehicle model (211, 212) is used to determine a case-specific estimate for the carbon dioxide concentration (CO2) of the exhaust gas plume (40) depending on the vehicle in question and its driving situation. Invention improves the accuracy of determining the concentrations of the actual emission gases (NO, HC, CO) by eliminating the inaccuracy of the carbon dioxide concentration (CO2) values.

Abstract: The invention relates to an optical measuring head for measuring a Raman spectrum and to a method of manufacturing an optical measuring head. The measuring head comprises a first optical fiber means for guiding radiation causing a Raman excitation to an object being measured, a second optical fiber means for guiding the optical radiation from the object being measured for measuring, and a high-pass filter that is made of a semi-conducting material for filtering the optical radiation causing a Raman excitation from the radiation received from the object being measured before the radiation propagates to the second optical fiber means. A desired cut-on wavelength is adjusted for the high-pass filter by changing the thickness or impurity content of the high-pass filter.