Directive 2005/55/EC of the European Parliament and of the Council (repealed)Dangos y teitl llawn

Appendix 4 MEASUREMENT AND SAMPLING PROCEDURES

[F1 1. INTRODUCTION U.K.

Gaseous components, particulates, and smoke emitted by the engine submitted for testing shall be measured by the methods described in Annex V. The respective sections of Annex V describe the recommended analytical systems for the gaseous emissions (section 1), the recommended particulate dilution and sampling systems (section 2), and the recommended opacimeters for smoke measurement (section 3).

For the ESC, the gaseous components shall be determined in the raw exhaust gas. Optionally, they may be determined in the diluted exhaust gas, if a full flow dilution system is used for particulate determination. Particulates shall be determined with either a partial flow or a full flow dilution system.

For the ETC, the following systems may be used

• a CVS full flow dilution system for determining gaseous and particulate emissions (double dilution systems are permissible),

  or

• a combination of raw exhaust measurement for the gaseous emissions and a partial flow dilution system for particulate emissions,

  or

• any combination of the two principles (e.g. raw gaseous measurement and full flow particulate measurement).]

Textual Amendments

F1 Substituted by 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).

2. DYNAMOMETER AND TEST CELL EQUIPMENT U.K.

The following equipment shall be used for emission tests of engines on engine dynamometers.

2.1. Engine dynamometer U.K.

An engine dynamometer shall be used with adequate characteristics to perform the test cycles described in Appendices 1 and 2 to this Annex. The speed measuring system shall have an accuracy of ± 2 % of reading. The torque measuring system shall have an accuracy of ± 3 % of reading in the range > 20 % of full scale, and an accuracy of ± 0,6 % of full scale in the range ≤ 20 % of full scale.

[F1 2.2. Other instruments U.K.

Measuring instruments for fuel consumption, air consumption, temperature of coolant and lubricant, exhaust gas pressure and intake manifold depression, exhaust gas temperature, air intake temperature, atmospheric pressure, humidity and fuel temperature shall be used, as required. These instruments shall satisfy the requirements given in table 9:

Table 9

Accuracy of measuring instruments

Measuring Instrument	Accuracy
Fuel Consumption	±2 % of Engine's Maximum Value
Air Consumption	±2 % of reading or ±1 % of engine's maximum value whichever is greater
Exhaust Gas Flow	±2, % of reading or ±1,5 % of engine's maximum value whichever is greater
Temperatures ≤ 600 K (327 °C)	±2 K Absolute
Temperatures ≥ 600 K (327 °C)	±1 % of Reading
Atmospheric Pressure	± 0,1 kPa Absolute
Exhaust Gas Pressure	± 0,2 kPa Absolute
Intake Depression	± 0,05 kPa Absolute
Other Pressures	± 0,1 kPa Absolute
Relative Humidity	±3 % Absolute
Absolute Humidity	±5 % of Reading
Dilution Air Flow	±2 % of Reading
Diluted Exhaust Gas Flow	±2 % of Reading]

F2 2.3. Exhaust gas flow U.K.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Textual Amendments

F2 Deleted by 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).

F2 2.4. Diluted exhaust gas flow U.K.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

[F1 3. DETERMINATION OF THE GASEOUS COMPONENTS U.K.

3.1. General analyser specifications U.K.

The analysers shall have a measuring range appropriate for the accuracy required to measure the concentrations of the exhaust gas components (section 3.1.1). It is recommended that the analysers be operated such that the measured concentration falls between 15 % and 100 % of full scale.

If read-out systems (computers, data loggers) can provide sufficient accuracy and resolution below 15 % of full scale, measurements below 15 % of full scale are also acceptable. In this case, additional calibrations of at least 4 non-zero nominally equally spaced points are to be made to ensure the accuracy of the calibration curves according to section 1.6.4 of Appendix 5 to this Annex.

The electromagnetic compatibility (EMC) of the equipment shall be on a level as to minimise additional errors.

3.1.1. Accuracy U.K.

The analyser shall not deviate from the nominal calibration point by more than ±2 % of the reading over the whole measurement range except zero, or ± 0,3 % of full scale whichever is larger. The accuracy shall be determined according to the calibration requirements laid down in section 1.6 of Appendix 5 to this Annex.

Note: For the purpose of this Directive, accuracy is defined as the deviation of the analyser reading from the nominal calibration values using a calibration gas (= true value). U.K.

3.1.2. Precision U.K.

The precision, defined as 2,5 times the standard deviation of 10 repetitive responses to a given calibration or span gas, has to be not greater than ±1 % of full scale concentration for each range used above 155 ppm (or ppmC) or ±2 % of each range used below 155 ppm (or ppmC).

3.1.3. Noise U.K.

The analyser peak-to-peak response to zero and calibration or span gases over any 10 second period shall not exceed 2 % of full scale on all ranges used.

3.1.4. Zero drift U.K.

Zero response is defined as the mean response, including noise, to a zero gas during a 30 seconds time interval. The drift of the zero response during a one hour period shall be less than 2 % of full scale on the lowest range used.

3.1.5. Span drift U.K.

Span response is defined as the mean response, including noise, to a span gas during a 30 seconds time interval. The drift of the span response during a one hour period shall be less than 2 % of full scale on the lowest range used.

3.1.6. Rise time U.K.

The rise time of the analyser installed in the measurement system shall not exceed 3,5 s.

Note: Only evaluating the response time of the analyser alone will not clearly define the suitability of the total system for transient testing. Volumes and especially dead volumes through out the system will not only effect the transportation time from the probe to the analyser, but also effect the rise time. Also transport times inside of an analyser would be defined as analyser response time, like the converter or water traps inside NO _x analysers. The determination of the total system response time is described in section 1.5 of Appendix 5 to this Annex. U.K.

3.2. Gas drying U.K.

The optional gas drying device must have a minimal effect on the concentration of the measured gases. Chemical dryers are not an acceptable method of removing water from the sample.

3.3. Analysers U.K.

Sections 3.3.1 to 3.3.4 describe the measurement principles to be used. A detailed description of the measurement systems is given in Annex V. The gases to be measured shall be analysed with the following instruments. For non-linear analysers, the use of linearising circuits is permitted.

3.3.1. Carbon monoxide (CO) analysis U.K.

The carbon monoxide analyser shall be of the Non-Dispersive InfraRed (NDIR) absorption type.

3.3.2. Carbon dioxide (CO ₂ ) analysis U.K.

The carbon dioxide analyser shall be of the Non-Dispersive InfraRed (NDIR) absorption type.

3.3.3. Hydrocarbon (HC) analysis U.K.

For diesel and LPG fuelled gas engines, the hydrocarbon analyser shall be of the Heated Flame Ionisation Detector (HFID) type with detector, valves, pipework, etc. heated so as to maintain a gas temperature of 463 K ±10 K (190 ±10 °C). For NG fuelled gas engines, the hydrocarbon analyser may be of the non heated Flame Ionisation Detector (FID) type depending upon the method used (see section 1.3 of Annex V).

3.3.4. Non-Methane Hydrocarbon (NMHC) analysis (NG fuelled gas engines only) U.K.

Non-methane hydrocarbons shall be determined by either of the following methods:

3.3.4.1. Gas chromatographic (GC) method U.K.

Non-methane hydrocarbons shall be determined by subtraction of the methane analysed with a Gas Chromatograph (GC) conditioned at 423 K (150 °C) from the hydrocarbons measured according to section 3.3.3.

3.3.4.2. Non-Methane Cutter (NMC) method U.K.

The determination of the non-methane fraction shall be performed with a heated NMC operated in line with an FID as per section 3.3.3 by subtraction of the methane from the hydrocarbons.

3.3.5. Oxides of Nitrogen (NO _x ) analysis U.K.

The oxides of nitrogen analyser shall be of the ChemiLuminescent Detector (CLD) or Heated ChemiLuminescent Detector (HCLD) type with a NO ₂ /NO converter, if measured on a dry basis. If measured on a wet basis, a HCLD with converter maintained above 328 K (55 °C) shall be used, provided the water quench check (see section 1.9.2.2 of Appendix 5 to this Annex) is satisfied.

3.3.6. Air-to-fuel measurement U.K.

The air to fuel measurement equipment used to determine the exhaust gas flow as specified in section 4.2.5 of Appendix 2 to this Annex shall be a wide range air to fuel ratio sensor or lambda sensor of Zirconia type. The sensor shall be mounted directly on the exhaust pipe where the exhaust gas temperature is high enough to eliminate water condensation.

The accuracy of the sensor with incorporated electronics shall be within:

±3 % of reading

λ < 2

±5 % of reading

2 ≤ λ < 5

±10 % of reading

5 ≤ λ

To fulfil the accuracy specified above, the sensor shall be calibrated as specified by the instrument manufacturer.

3.4. Sampling of Gaseous Emissions U.K.

3.4.1. Raw exhaust gas U.K.

The gaseous emissions sampling probes shall be fitted at least 0,5 m or 3 times the diameter of the exhaust pipe — whichever is the larger — upstream of the exit of the exhaust gas system but sufficiently close to the engine as to ensure an exhaust gas temperature of at least 343 K (70 °C) at the probe.

In the case of a multi-cylinder engine with a branched exhaust manifold, the inlet of the probe shall be located sufficiently far downstream so as to ensure that the sample is representative of the average exhaust emissions from all cylinders. In multi-cylinder engines having distinct groups of manifolds, such as in a ‘Vee’ engine configuration, it is recommended to combine the manifolds upstream of the sampling probe. If this is not practical, it is permissible to acquire a sample from the group with the highest CO ₂ emission. Other methods which have been shown to correlate with the above methods may be used. For exhaust emission calculation the total exhaust mass flow shall be used.

If the engine is equipped with an exhaust aftertreatment system, the exhaust sample shall be taken downstream of the exhaust aftertreatment system.

3.4.2. Diluted exhaust gas U.K.

The exhaust pipe between the engine and the full flow dilution system shall conform to the requirements of section 2.3.1 of Annex V (EP).

The gaseous emissions sample probe(s) shall be installed in the dilution tunnel at a point where the dilution air and exhaust gas are well mixed, and in close proximity to the particulates sampling probe.

Sampling can generally be done in two ways:

• the pollutants are sampled into a sampling bag over the cycle and measured after completion of the test,

• the pollutants are sampled continuously and integrated over the cycle; this method is mandatory for HC and NO _x .

4. DETERMINATION OF THE PARTICULATES U.K.

The determination of the particulates requires a dilution system. Dilution may be accomplished by a partial flow dilution system or a full flow double dilution system. The flow capacity of the dilution system shall be large enough to completely eliminate water condensation in the dilution and sampling systems. The temperature of the diluted exhaust gas shall be below 325 K (52 °C) (1) immediately upstream of the filter holders. Humidity control of the dilution air before entering the dilution system is permitted, and especially dehumidifying is useful if dilution air humidity is high. The temperature of the dilution air shall be higher than 288 K (15 °C) in close proximity to the entrance into the dilution tunnel.

The partial flow dilution system has to be designed to extract a proportional raw exhaust sample from the engine exhaust stream, thus responding to excursions in the exhaust stream flow rate, and introduce dilution air to this sample to achieve a temperature below 325 K (52 °C) at the test filter. For this it is essential that the dilution ratio or the sampling ratio r _dil or r _s be determined such that the accuracy limits of section 3.2.1 of Appendix 5 to this Annex are fulfilled. Different extraction methods can be applied, whereby the type of extraction used dictates to a significant degree the sampling hardware and procedures to be used (section 2.2 of Annex V).

In general, the particulate sampling probe shall be installed in close proximity to the gaseous emissions sampling probe, but sufficiently distant as to not cause interference. Therefore, the installation provisions of section 3.4.1 also apply to particulate sampling. The sampling line shall conform to the requirements of section 2 of Annex V.

In the case of a multi-cylinder engine with a branched exhaust manifold, the inlet of the probe shall be located sufficiently far downstream so as to ensure that the sample is representative of the average exhaust emissions from all cylinders. In multi-cylinder engines having distinct groups of manifolds, such as in a ‘ Vee ’ engine configuration, it is recommended to combine the manifolds upstream of the sampling probe. If this is not practical, it is permissible to acquire a sample from the group with the highest particulate emission. Other methods which have been shown to correlate with the above methods may be used. For exhaust emission calculation the total exhaust mass flow shall be used.

To determine the mass of the particulates, a particulate sampling system, particulate sampling filters, a microgram balance, and a temperature and humidity controlled weighing chamber, are required.

For particulate sampling, the single filter method shall be applied which uses one filter (see section 4.1.3) for the whole test cycle. For the ESC, considerable attention must be paid to sampling times and flows during the sampling phase of the test.

4.1. Particulate sampling filters U.K.

The diluted exhaust shall be sampled by a filter that meets the requirements of sections 4.1.1 and 4.1.2 during the test sequence.

4.1.1. Filter specification U.K.

Fluorocarbon coated glass fiber filters are required. All filter types shall have a 0,3 μm DOP (di-octylphthalate) collection efficiency of at least 99 % at a gas face velocity between 35 and 100 cm/s.

4.1.2. Filter size U.K.

Particulate filters with a diameter of 47 mm or 70 mm are recommended. Larger diameter filters are acceptable (section 4.1.4), but smaller diameter filters are not permitted.

4.1.3. Filter face velocity U.K.

A gas face velocity through the filter of 35 to 100 cm/s shall be achieved. The pressure drop increase between the beginning and the end of the test shall be no more than 25 kPa.

4.1.4. Filter loading U.K.

The required minimum filter loadings for the most common filter sizes are shown in table 10. For larger filter sizes, the minimum filter loading shall be 0,065 mg/ 1 000  mm ² filter area.

Table 10

Minimum Filter Loadings

Filter Diameter (mm)	Minimum loading (mg)
47	0,11
70	0,25
90	0,41
110	0,62

If, based on previous testing, the required minimum filter loading is unlikely to be reached on a test cycle after optimisation of flow rates and dilution ratio, a lower filter loading may be acceptable, with the agreement of the parties involved, if it can be shown to meet the accuracy requirements of section 4.2, e.g. with a 0,1 μg balance.

4.1.5. Filter holder U.K.

For the emissions test, the filters shall be placed in a filter holder assembly meeting the requirements of section 2.2 of Annex V. The filter holder assembly shall be of a design that provides an even flow distribution across the filter stain area. Quick acting valves shall be located either upstream or downstream of the filter holder. An inertial pre-classifier with a 50 % cut point between 2,5 μm and 10 μm may be installed immediately upstream of the filter holder. The use of the pre-classifier is strongly recommended if an open tube sampling probe facing upstream into the exhaust flow is used.

4.2. Weighing chamber and analytical balance specifications U.K.

4.2.1. Weighing chamber conditions U.K.

The temperature of the chamber (or room) in which the particulate filters are conditioned and weighed shall be maintained to within 295 K ±3 K (22 °C ±3 °C) during all filter conditioning and weighing. The humidity shall be maintained to a dewpoint of 282,5 K ±3 K (9,5 °C ±3 °C) and a relative humidity of 45 % ±8 %.

4.2.2. Reference filter weighing U.K.

The chamber (or room) environment shall be free of any ambient contaminants (such as dust) that would settle on the particulate filters during their stabilisation. Disturbances to weighing room specifications as outlined in section 4.2.1 will be allowed if the duration of the disturbances does not exceed 30 minutes. The weighing room should meet the required specifications prior to personal entrance into the weighing room. At least two unused reference filters shall be weighed within 4 hours of, but preferably at the same time as the sample filter weightings. They shall be the same size and material as the sample filters.

If the average weight of the reference filters changes between sample filter weightings by more than 10 μg, then all sample filters shall be discarded and the emissions test repeated.

If the weighing room stability criteria outlined in section 4.2.1 is not met, but the reference filter weightings meet the above criteria, the engine manufacturer has the option of accepting the sample filter weights or voiding the tests, fixing the weighing room control system and re-running the test.

4.2.3. Analytical balance U.K.

The analytical balance used to determine the filter weight shall have a precision (standard deviation) of at least 2 μg and a resolution of at least 1 μg (1 digit = 1 μg) specified by the balance manufacturer.

4.2.4. Elimination of static electricity effects U.K.

To eliminate the effects of static electricity, the filters shall be neutralized prior to weighing, e.g. by a Polonium neutralizer, a Faraday cage or a device of similar effect.

4.2.5. Specifications for flow measurement U.K.

4.2.5.1. General requirements U.K.

Absolute accuracies of flow meter or flow measurement instrumentation shall be as specified in section 2.2.

4.2.5.2. Special provisions for partial flow dilution systems U.K.

For partial flow dilution systems, the accuracy of the sample flow q _mp is of special concern, if not measured directly, but determined by differential flow measurement:

q _mp = q _mdew – q _mdw

In this case an accuracy of ±2 % for q _mdew and q _mdw is not sufficient to guarantee acceptable accuracies of q _mp . If the gas flow is determined by differential flow measurement, the maximum error of the difference shall be such that the accuracy of q _mp is within ±5 % when the dilution ratio is less than 15. It can be calculated by taking root-mean-square of the errors of each instrument.

Acceptable accuracies of q _mp can be obtained by either of the following methods:

The absolute accuracies of q _mdew and q _mdw are ±0,2 % which guarantees an accuracy of q _mp of ≤ 5 % at a dilution ratio of 15. However, greater errors will occur at higher dilution ratios;

calibration of q _mdw relative to q _mdew is carried out such that the same accuracies for q _mp as in a) are obtained. For the details of such a calibration see section 3.2.1 of Appendix 5 to Annex III;

the accuracy of q _mp is determined indirectly from the accuracy of the dilution ratio as determined by a tracer gas, e.g. CO ₂ . Again, accuracies equivalent to method a) for q _mp are required;

the absolute accuracy of q _mdew and q _mdw is within ±2 % of full scale, the maximum error of the difference between q _mdew and q _mdw is within 0,2 %, and the linearity error is within ±0,2 % of the highest q _mdew observed during the test.]

5. DETERMINATION OF SMOKE U.K.

This section provides specifications for the required and optional test equipment to be used for the ELR test. The smoke shall be measured with an opacimeter having an opacity and a light absorption coefficient readout mode. The opacity readout mode shall only be used for calibration and checking of the opacimeter. The smoke values of the test cycle shall be measured in the light absorption coefficient readout mode.

5.1. General requirements U.K.

The ELR requires the use of a smoke measurement and data processing system which includes three functional units. These units may be integrated into a single component or provided as a system of interconnected components. The three functional units are:

• an opacimeter meeting the specifications of Annex V, Section 3,

• a data processing unit capable of performing the functions described in Annex III, Appendix 1, Section 6,

• a printer and/or electronic storage medium to record and output the required smoke values specified in Annex III, Appendix 1, Section 6.3.

5.2. Specific requirements U.K.

5.2.1. Linearity U.K.

The linearity shall be within ± 2 % opacity.

5.2.2. Zero drift U.K.

The zero drift during a one hour period shall not exceed ± 1 % opacity.

5.2.3. Opacimeter display and range U.K.

For display in opacity, the range shall be 0-100 % opacity, and the readability 0,1 % opacity. For display in light absorption coefficient, the range shall be 0-30 m^-1 light absorption coefficient, and the readability 0,01 m^-1 light absorption coefficient.

5.2.4. Instrument response time U.K.

The physical response time of the opacimeter shall not exceed 0,2 s. The physical response time is the difference between the times when the output of a rapid response receiver reaches 10 and 90 % of the full deviation when the opacity of the gas being measured is changed in less than 0,1 s.

The electrical response time of the opacimeter shall not exceed 0,05 s. The electrical response time is the difference between the times when the opacimeter output reaches 10 and 90 % of the full scale when the light source is interrupted or completely extinguished in less than 0,01 s.

5.2.5. Neutral density filters U.K.

Any neutral density filter used in conjunction with opacimeter calibration, linearity measurements, or setting span shall have its value known to within 1,0 % opacity. The filter's nominal value must be checked for accuracy at least yearly using a reference traceable to a national or international standard.

Neutral density filters are precision devices and can easily be damaged during use. Handling should be minimised and, when required, should be done with care to avoid scratching or soiling of the filter.

(1)

[F1 The Commission shall review the temperature upstream of the filter holder, 325 K (52 °C), and, if necessary propose an alternative temperature to be applicable for type-approval of new types from 1 October 2008 .]

Textual Amendments

F1 Substituted by 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).