(iv)

Commission Directive 2005/78/EC of 14 November 2005 implementing Directive 2005/55/EC of the European Parliament and of the Council on the approximation of the laws of the Member States relating to the measures to be taken against the emission of gaseous and particulate pollutants from compression-ignition engines for use in vehicles, and the emission of gaseous pollutants from positive ignition engines fuelled with natural gas or liquefied petroleum gas for use in vehicles and amending Annexes I, II, III, IV and VI thereto (Text with EEA relevance) · European Union

Former section 1.5 is replaced by the following: ‘1.6. Calibration 1.6.1. Instrument assembly The instrument assembly shall be calibrated and calibration curves checked against standard gases. The same gas flow rates shall be used as when sampling exhaust. 1.6.2. Warming-up time The warming-up time should be according to the recommendations of the manufacturer. If not specified, a minimum of two hours is recommended for warming up the analysers. 1.6.3. NDIR and HFID analyser The NDIR analyser shall be tuned, as necessary, and the combustion flame of the HFID analyser shall be optimised (section 1.8.1). 1.6.4. Establishment of the calibration curve 1.6.5. Alternative methods If it can be shown that alternative technology (e.g. computer, electronically controlled range switch, etc.) can give equivalent accuracy, then these alternatives may be used. 1.6.6. Calibration of tracer gas analyser for exhaust flow measurement The calibration curve shall be established by at least 6 calibration points (excluding zero) approximately equally spaced over the operating range. The highest nominal concentration shall be equal to or higher than 90 % of full scale. The calibration curve is calculated by the method of least squares. The calibration points shall not differ from the least-squares best-fit line by more than ± 2 % of reading or ± 0,3 % of full scale whichever is larger. The analyser shall be set at zero and spanned prior to the test run using a zero gas and a span gas whose nominal value is more than 80 % of the analyser full scale.’ Each normally used operating range shall be calibrated Using purified synthetic air (or nitrogen), the CO, CO2, NOx and HC analysers shall be set at zero The appropriate calibration gases shall be introduced to the analysers, the values recorded, and the calibration curve established The calibration curve shall be established by at least 6 calibration points (excluding zero) approximately equally spaced over the operating range. The highest nominal concentration shall be equal to or higher than 90 % of full scale The calibration curve shall be calculated by the method of least-squares. A best-fit linear or non-linear equation may be used The calibration points shall not differ from the least-squares best-fit line by more than ± 2 % of reading or ± 0,3 % of full scale whichever is larger The zero setting shall be rechecked and the calibration procedure repeated, if necessary.

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Source: EUR-Lex (Cellar) · retrieved 2026-11-10 · Text as adopted (Official Journal); later amendments are not incorporated in this text.