An exhaust-gas analyser system configured to determine the concentration of one or more exhaust gases of an automotive internal-combustion engine; said system comprising: - an infrared multi-detecting device provided with: • a gas-analysis chamber structured to contain the exhaust gases to be analysed; • infrared emitter means configured to emit infrared radiation in said analysis chamber towards the exhaust gases contained therein; and • multi-detecting infrared means configured to generate electrical measurement quantities on the basis of absorption of said radiation by the exhaust gases present within said analysis chamber; - electronic control means, which are configured to determine the concentrations of one or more exhaust gases, based on a series of electrical measurement quantities (Vmi) provided by said multi-detecting infrared means and of an electrical reference quantity; said system being characterized by comprising: - pumping means connected to said analysis chamber for performing an intake within the analysis chamber itself; and wherein, said electronic control means are moreover configured to: - control said pumping means in such a way as to take in air/residual gases contained in the analysis chamber until a condition of absence of gases in the chamber itself is reached, in which the pressure inside the analysis chamber reaches a pre-set minimum pressure; - control said emitter means so as to emit infrared radiation into said analysis chamber; and - determine said electrical reference quantity based on the electrical quantity of the electrical signals generated by said multi-detecting infrared means as a function of the radiation detected in said condition of absence of gases. - an infrared multi-detecting device provided with: • a gas-analysis chamber structured to contain the exhaust gases to be analysed; • infrared emitter means configured to emit infrared radiation in said analysis chamber towards the exhaust gases contained therein; and • multi-detecting infrared means configured to generate electrical measurement quantities on the basis of absorption of said radiation by the exhaust gases present within said analysis chamber; • a gas-analysis chamber structured to contain the exhaust gases to be analysed; • infrared emitter means configured to emit infrared radiation in said analysis chamber towards the exhaust gases contained therein; and • multi-detecting infrared means configured to generate electrical measurement quantities on the basis of absorption of said radiation by the exhaust gases present within said analysis chamber; - electronic control means, which are configured to determine the concentrations of one or more exhaust gases, based on a series of electrical measurement quantities (Vmi) provided by said multi-detecting infrared means and of an electrical reference quantity; - pumping means connected to said analysis chamber for performing an intake within the analysis chamber itself; and wherein, said electronic control means are moreover configured to: - control said pumping means in such a way as to take in air/residual gases contained in the analysis chamber until a condition of absence of gases in the chamber itself is reached, in which the pressure inside the analysis chamber reaches a pre-set minimum pressure; - control said emitter means so as to emit infrared radiation into said analysis chamber; and - determine said electrical reference quantity based on the electrical quantity of the electrical signals generated by said multi-detecting infrared means as a function of the radiation detected in said condition of absence of gases.