Commission Regulation (EU) 2018/1832Show full title

ANNEX IV U.K.

‘ANNEX VI U.K. DETERMINATION OF EVAPORATIVE EMISSIONS (TYPE 4 TEST)

1. Introduction

This Annex provides the method to determine the levels of evaporative emission from light-duty vehicles in a repeatable and reproducible manner designed to be representative of real world vehicle operation.

2. Reserved

3. Definitions

For the purposes of this Annex, the following definitions shall apply:

3.1. Test equipment

3.1.1. “Accuracy” means the difference between a measured value and a reference value, traceable to a national standard and describes the correctness of a result.

3.1.2. “Calibration” means the process of setting a measurement system's response so that its output agrees with a range of reference signals.

3.2. Hybrid electric vehicles

3.2.1. “Charge-depleting operating condition” means an operating condition in which the energy stored in the Rechargeable Electric Energy Storage System (REESS) may fluctuate but decreases on average while the vehicle is driven until transition to charge-sustaining operation.

3.2.2. “Charge-sustaining operating condition” means an operating condition in which the energy stored in the REESS may fluctuate but, on average, is maintained at a neutral charging balance level while the vehicle is driven.

3.2.3. “Not off-vehicle charging hybrid electric vehicle” (NOVC-HEV) means a hybrid electric vehicle that cannot be charged from an external source.

3.2.4. “Off-vehicle charging hybrid electric vehicle” (OVC-HEV) means a hybrid electric vehicle that can be charged from an external source.

3.2.5. “Hybrid electric vehicle” (HEV) means a hybrid vehicle where one of the propulsion energy converters is an electric machine.

3.2.6. “Hybrid vehicle” (HV) means a vehicle equipped with a powertrain containing at least two different categories of propulsion energy converters and at least two different categories of propulsion energy storage systems.

3.3. Evaporative emission

3.3.1. “Fuel tank system” means the devices which allow storing the fuel, comprising the fuel tank, the fuel filler, the filler cap and the fuel pump when it is fitted in or on the fuel tank.

3.3.2. “Fuel system” means the components which store or transport fuel on board the vehicle and comprise the fuel tank system, all fuel and vapour lines, any non-tank mounted fuel pumps and the activated carbon canister.

3.3.3. “Butane working capacity” (BWC) means the mass of butane which a canister can adsorb.

3.3.4. “BWC300” means the butane working capacity after 300 cycles of fuel ageing cycles experienced.

3.3.5. “Permeability Factor” (PF) means the factor determined from hydrocarbon losses over a period of time and used to determine the final evaporative emissions.

3.3.6. “Monolayer non-metal tank” means a fuel tank constructed with a single layer of non-metal material including fluorinated/sulfonated materials.

3.3.7. “Multilayer tank” means a fuel tank constructed with at least two different layered materials, one of which is a hydrocarbon barrier material.

3.3.8. “Sealed fuel tank system” means a fuel tank system where the fuel vapours do not vent during parking over the 24-hour diurnal cycle defined in Appendix 2 to Annex 7 of UN/ECE Regulation No 83 when performed with a reference fuel defined in Section A.1 of Annex IX to this Regulation.

3.3.9. “Evaporative emissions” means in the context of this Regulation the hydrocarbon vapours lost from the fuel system of a motor vehicle during parking and immediately before refuelling of a sealed fuel tank.

3.3.10. “Mono-fuel gas vehicle” means a mono-fuel vehicle that runs primarily on liquefied petroleum gas, natural gas/biomethane, or hydrogen but may also have a petrol system for emergency purposes or starting only, where the petrol tank does not contain more than 15 litres of petrol.

3.3.11. “Depressurisation puff loss” means hydrocarbons venting from a sealed fuel tank system pressure relief exclusively through the vapour storage unit allowed by the system.

3.3.12. “Depressurisation puff loss overflow” are the depressurisation puff loss hydrocarbons that pass through the vapour storage unit during depressurisation.

3.3.13. “Fuel tank relief pressure” is the minimum pressure value at which the sealed fuel tank system starts venting in response only to pressure inside the tank.

3.3.14. “Auxiliary canister” is the canister used to measure depressurisation puff loss overflow.

3.3.15. “2 gram breakthrough” shall be considered accomplished when the cumulative quantity of hydrocarbons emitted from the activated carbon canister equals 2 grams.

4. Abbreviations

General abbreviations

BWC	Butane working capacity
PF	Permeability factor
APF	Assigned permeability factor
OVC-HEV	Off-vehicle charging hybrid electric vehicle
NOVC-HEV	Not off-vehicle charging hybrid electric vehicle
WLTC	Worldwide light-duty test cycle
REESS	Rechargeable electric energy storage system

5. General requirements

5.1. The vehicle and its components liable to affect the evaporative emissions shall be designed, constructed and assembled so as to enable the vehicle in normal use and under normal conditions of use such as humidity, rain, snow, heat, cold, sand, dirt, vibrations, wear, etc. to comply with the provisions of this Regulation during its useful life.

5.1.1. This shall include the security of all hoses, joints and connections used within the evaporative emission control systems.

5.1.2. For vehicles with a sealed fuel tank system, this shall also include having a system which, just before refuelling, releases the tank pressure exclusively through a vapour storage unit which has the sole function of storing fuel vapour. This ventilation route shall also be the only one used when the tank pressure exceeds its safe working pressure.

5.2. The test vehicle shall be selected in accordance with paragraph 5.5.2.

5.3. Vehicle testing condition

5.3.1. The types and amounts of lubricants and coolant for emissions testing shall be as specified for normal vehicle operation by the manufacturer.

5.3.2. The type of fuel for testing shall be as specified in Section A.1 of Annex IX.

5.3.3. All evaporative emissions controlling systems shall be in working order.

5.3.4. The use of any defeat device is prohibited in accordance with the provisions of Article 5(2) of Regulation (EC) No 715/2007.

5.4. Provisions for electronic system security

5.4.1. The provisions for electronic system security shall be those specified in paragraph 2.3. of Annex I.

5.5. Evaporative emission family

5.5.1. Only vehicles that are identical with respect to the characteristics listed in (a), (c) and (d), technically equivalent with respect to the characteristics listed in (b) and similar or, where applicable, within the stated tolerance regarding the characteristics listed in (e) and (f) may be part of the same evaporative emission family:

(a)

Fuel tank system material and construction;

(b)

Vapour hose material, fuel line material and connection technique;

(c)

Sealed tank or non-sealed tank system;

(d)

Fuel tank relief valve setting (air ingestion and relief);

(e)

Canister butane working capacity (BWC300) within a 10 per cent range of the highest value (for canisters with the same type of charcoal, the volume of charcoal shall be within 10 per cent of that for which the BWC300 was determined);

(f)

Purge control system (for example, type of valve, purge control strategy).

5.5.2. The vehicle shall be considered to produce worst-case evaporative emissions and shall be used for testing if it has the largest ratio of fuel tank capacity to canister butane working capacity within the family. The vehicle selection shall be agreed in advance with the approval authority.

5.5.3. The use of any innovative system calibration, configuration, or hardware related to the evaporative control system shall place the vehicle model in a different family.

5.5.4. Evaporative Emissions Family Identifier

Each of the evaporative emission families defined in paragraph 5.5.1. shall be attributed a unique identifier of the following format:

EV-nnnnnnnnnnnnnnn-WMI-x

Where:

nnnnnnnnnnnnnnn is a string with a maximum of fifteen characters, restricted to using the characters 0-9, A-Z and the underscore character ‘_’.

WMI (world manufacturer identifier) is a code that identifies the manufacturer in a unique manner defined in ISO 3780:2009.

x shall be set to ‘1’ or ‘0’ in accordance with the following provisions:

(a)

With the agreement of the approval authority and the owner of the WMI, the number shall be set to ‘1’ where a vehicle family is defined for the purpose of covering vehicles of:

(i)

a single manufacturer with one single WMI code;

(ii)

a manufacturer with several WMI codes, but only in cases when one WMI code is to be used;

(iii)

more than one manufacturer, but only in cases when one WMI code is to be used.

In the cases (i), (ii) and (iii), the family identifier code shall consist of one unique string of n-characters and one unique WMI code followed by ‘1’.

(b)

With the agreement of the approval authority, the number shall be set to ‘0’ in the case that a vehicle family is defined based on the same criteria as the corresponding vehicle family defined in accordance with point (a), but the manufacturer chooses to use a different WMI. In this case the family identifier code shall consist of the same string of n-characters as the one determined for the vehicle family defined in accordance with point (a) and a unique WMI code which shall be different from any of the WMI codes used under case (a), followed by ‘0’.

5.6. The approval authority shall not grant type approval if the information provided is insufficient to demonstrate that the evaporative emissions are effectively limited during the normal use of the vehicle.

6. Performance requirements

6.1. Limit values

The limit value shall be that specified in Table 3 of Annex I to Regulation (EC) No 715/2007.

Appendix 1 U.K. Type 4 test procedures and test conditions

1. Introduction

This Annex describes the procedure for the Type 4 test which determines the evaporative emission of vehicles.

2. Technical requirements

2.1. The procedure includes the evaporative emissions test and two additional tests, one for the ageing of carbon canisters, as described in paragraph 5.1. of this Appendix, and one for the permeability of the fuel tank system, as described in paragraph 5.2. of this Appendix. The evaporative emissions test (Figure VI.4) determines hydrocarbon evaporative emissions as a consequence of diurnal temperature fluctuations and hot soaks during parking.

2.2. In the case that the fuel system contains more than one carbon canister, all references to the term “canister” in this Annex shall apply to each canister.

3. Vehicle

The vehicle shall be in good mechanical condition and have been run-in and driven at least 3 000 km before the test. For the purpose of the determination of evaporative emissions, the mileage and the age of the vehicle used for certification shall be included in all relevant test reports. The evaporative emission control system shall be connected and functioning correctly during the run-in period. A carbon canister aged in accordance with the procedure described in paragraph 5.1. of this Appendix shall be used.

4. Test equipment

4.1. Chassis dynamometer

The chassis dynamometer shall meet the requirements of paragraph 2. of Sub-Annex 5 of Annex XXI.

4.2. Evaporative emission measurement enclosure

The evaporative emission measurement enclosure shall meet the requirements of paragraph 4.2. of Annex 7 of UN/ECE Regulation No 83.

4.3. Analytical systems

The analytical systems shall meet the requirements of paragraph 4.3. of Annex 7 of UN/ECE Regulation No 83. Continuous measuring of hydrocarbons is not mandatory unless the fixed volume type enclosure is used.

4.4. Temperature recording system

The temperature recording shall meet the requirements of paragraph 4.5. of Annex 7 of UN/ECE Regulation No 83.

4.5. Pressure recording system

The pressure recording shall meet the requirements of paragraph 4.6. of Annex 7 of UN/ECE Regulation No 83, except that the accuracy and resolution of the pressure recording system defined in paragraph 4.6.2. of Annex 7 of UN/ECE Regulation No 83 shall be:

(a)

Accuracy: ± 0,3 kPa

(b)

Resolution: 0,025 kPa

4.6. Fans

The fans shall meet the requirements of paragraph 4.7. of Annex 7 of UN/ECE Regulation No 83, except that the capacity of the blowers shall be 0,1 to 0,5 m³/sec instead of 0,1 to 0,5 m³/min.

4.7. Calibration gases

The gases shall meet the requirements of paragraph 4.8. of Annex 7 of UN/ECE Regulation No 83.

4.8. Additional Equipment

The additional equipment shall meet the requirements of paragraph 4.9. of Annex 7 of UN/ECE Regulation No 83.

4.9. Auxiliary canister

The auxiliary canister should be identical to the main canister but not necessarily aged. The connection tube to the vehicle canister shall be as short as possible. The auxiliary canister shall be fully-purged with dry air prior to loading.

4.10. Canister weighing scale

The canister weighing scale shall have an accuracy of ±0,02 g.

5. Procedure for canister bench ageing and PF determination

5.1. Canister bench ageing

Before performing the hot soak and diurnal losses sequences, the canister shall be aged in accordance with the procedure described in Figure VI.1.

Figure VI.1 Canister bench ageing procedure

5.1.1. Ageing through exposure to temperature cycling

The canister shall be cycled between temperatures from – 15 °C to 60 °C in a dedicated temperature enclosure with 30 minutes of stabilisation at – 15 °C and 60 °C. Each cycle shall last 210 minutes (see Figure VI.2).

The temperature gradient shall be as close as possible to 1 °C/min. No forced air flow should pass through the canister.

The cycle shall be repeated 50 times consecutively. In total, this procedure lasts 175 hours.

Figure VI.2 Temperature conditioning cycle

5.1.2. Ageing through exposure to vibration

Following the temperature ageing procedure, the canister shall be shaken vertically with the canister mounted as per its orientation in the vehicle with an overall Grms > 1,5 m/sec² with a frequency of 30 ± 10 Hz. The test shall last 12 hours.

5.1.3. Ageing through exposure to fuel vapour and determining BWC300

5.1.3.1. Ageing shall consist of repeatedly loading with fuel vapour and purging with laboratory air.

5.1.3.1.1. After temperature and vibration ageing, the canister shall be further aged with a mixture of market fuel as specified in paragraph 5.1.3.1.1.1. of this Appendix and nitrogen or air with a 50 ± 15 per cent fuel vapour volume. The fuel vapour fill rate shall be 60 ± 20 g/h.

The canister shall be loaded to 2 gram breakthrough. As an alternative, loading shall be deemed to be completed when the hydrocarbon concentration level at the vent outlet reaches 3 000 ppm.

5.1.3.1.1.1. The market fuel used for this test shall fulfil the same requirements as a reference fuel with respect to:

(a)

Density at 15 °C;

(b)

Vapour pressure;

(c)

Distillation (70 °C, 100 °C, 150 °C);

(d)

Hydrocarbon analysis (olefins, aromatics, benzene only);

(e)

Oxygen content;

(f)

Ethanol content.

5.1.3.1.2. The canister shall be purged between 5 and 60 minutes after loading with 25 ± 5 litres per minute of emission laboratory air until 300 bed volume exchanges are reached.

5.1.3.1.3. The procedures set out in paragraphs 5.1.3.1.1. and 5.1.3.1.2. of this Appendix shall be repeated 300 times after which the canister shall be considered to be stabilised.

5.1.3.1.4. The procedure to measure the butane working capacity (BWC) with respect to the evaporative emission family in paragraph 5.5. shall consist of the following.

(a)

The stabilised canister shall be loaded to 2 gram breakthrough and subsequently purged a minimum of 5 times. Loading shall be performed with a mixture composed of 50 per cent butane and 50 per cent nitrogen by volume at a rate of 40 grams butane per hour.

(b)

Purging shall be performed in accordance with paragraph 5.1.3.1.2. of this Appendix.

(c)

The BWC shall be included in all relevant test reports after each loading.

(d)

BWC300 shall be calculated as the average of the last 5 BWCs.

5.1.3.2. If an aged canister is provided by a supplier, the manufacturer shall inform the approval authority in advance of the ageing process to enable the witnessing of any part of that process in the supplier's facilities.

5.1.3.3. The manufacturer shall provide the approval authority a test report including at least the following elements:

(a)

Type of activated carbon;

(b)

Loading rate;

(c)

Fuel specifications.

5.2. Determination of the PF of the fuel tank system (see Figure VI.3)

Figure VI.3 Determination of the PF

5.2.1. The fuel tank system representative of a family shall be selected and mounted on a rig in a similar orientation as in the vehicle. The tank shall be filled to 40 ± 2 per cent of its nominal capacity with reference fuel at a temperature of 18 °C ± 2 °C. The rig with the fuel tank system shall be placed in a room with a controlled temperature of 40 °C ± 2 °C for 3 weeks.

5.2.2. At the end of the third week, the tank shall be drained and refilled with reference fuel at a temperature of 18 °C ± 2 °C to 40 ± 2 per cent of its nominal tank capacity.

Within 6 to 36 hours, the rig with the fuel tank system shall be placed in an enclosure. The last 6 hours of this period shall be at an ambient temperature of 20 °C ± 2 °C. In the enclosure, a diurnal procedure shall be performed over the first 24-hour period of the procedure described in paragraph 6.5.9. of this Appendix. The fuel vapour in the tank shall be vented to the outside of the enclosure to eliminate the possibility of the tank venting emissions being counted as permeation. The HC emissions shall be measured and the value shall be included in all relevant test reports as HC_3W.

5.2.3. The rig with the fuel tank system shall be placed again in a room with a controlled temperature of 40 °C ± 2 °C for the remaining 17 weeks.

5.2.4. At the end of the seventeenth week, the tank shall be drained and refilled with reference fuel at a temperature of 18 °C ± 2 °C to 40 ± 2 per cent of its nominal tank capacity.

Within 6 to 36 hours, the rig with the fuel tank system shall be placed in an enclosure. The last 6 hours of this period shall be at an ambient temperature of 20 °C ± 2 °C. In the enclosure, a diurnal procedure shall be performed over a first period of 24 hours of the procedure described in accordance with paragraph 6.5.9. of this Appendix. The fuel tank system shall be vented to the outside of the enclosure to eliminate the possibility of the tank venting emissions being counted as permeation. The HC emissions shall be measured and the value shall be included in all relevant test reports in this case as HC_20W.

5.2.5. The PF is the difference between HC_20W and HC_3W in g/24h calculated to 3 significant digits using the following equation:

PF = HC_20w – HC_3W

5.2.6. If the PF is determined by a supplier, the vehicle manufacturer shall inform the approval authority in advance of the determination to allow witness check in the supplier's facility.

5.2.7. The manufacturer shall provide the approval authority with a test report containing at least the following:

(a)

A full description of the fuel tank system tested, including information on the type of tank tested, whether the tank is metal, monolayer non-metal or multilayer, and which types of materials are used for the tank and other parts of the fuel tank system;

(b)

The weekly mean temperatures at which the ageing was performed;

(c)

The HC measured at week 3 (HC_3W);

(d)

The HC measured at week 20 (HC_20W);

(e)

The resulting permeability factor (PF).

5.2.8. As an alternative to paragraphs 5.2.1. to 5.2.7. of this Appendix, a manufacturer using multilayer tanks or metal tanks may choose to use an Assigned Permeability Factor (APF) instead of performing the complete measurement procedure mentioned above:

APF multilayer/metal tank = 120 mg /24 h

Where the manufacturer chooses to use an APF, the manufacturer shall provide the approval authority with a declaration in which the type of tank is clearly specified as well as a declaration of the type of materials used.

6. Test procedure for the measurement of hot soak and diurnal losses

6.1. Vehicle preparation

The vehicle shall be prepared in accordance to paragraphs 5.1.1. and 5.1.2. of Annex 7 of UN/ECE Regulation No 83. At the request of the manufacturer and with approval of the approval authority, non-fuel background emission sources (e.g. paint, adhesives, plastics, fuel/vapour lines, tyres, and other rubber or polymer components) may be reduced to typical vehicle background levels before testing (e.g. baking of tyres at temperatures of 50 °C or higher for appropriate periods, baking of the vehicle, draining washer fluid).

For a sealed fuel tank system, the vehicle canisters shall be installed so that access to canisters and connection/disconnection of canisters can be done easily.

6.2. Mode selections and gear shift prescriptions

6.2.1. For vehicles with manual shift transmissions, the gear shift prescriptions specified in Sub-Annex 2 of Annex XXI shall apply.

6.2.2. In the case of pure ICE vehicles, the mode shall be selected in accordance with Sub-Annex 6 of Annex XXI.

6.2.3. In the case of NOVC-HEVs and OVC-HEVs, the mode shall be selected in accordance with Appendix 6 to Sub-Annex 8 of Annex XXI.

6.2.4. Upon request of the approval authority, the selected mode may be different from that described in paragraphs 6.2.2. and 6.2.3. of this Appendix.

6.3. Test conditions

The tests included in this Annex shall be performed using the test conditions specific to interpolation family vehicle H with the highest cycle energy demand of all the interpolation families included in the evaporative emission family being considered.

Alternatively, at the request of the approval authority, any cycle energy representative of a vehicle in the family may be used for the test.

6.4. Flow of the test procedure

The test procedure for non-sealed and sealed tank systems shall be followed in accordance with the flow chart described in Figure VI.4.

The sealed fuel tank systems shall be tested with one of 2 options. One option is to test the vehicle with one continuous procedure. Another option, called the stand-alone procedure, is to test the vehicle with two separate procedures which will allow repeating the dynamometer test and the diurnal tests without repeating the tank depressurisation puff loss overflow test and the depressurisation puff loss measurement.

Figure VI.4 Test procedure flow charts

6.5. Continuous test procedure for non-sealed fuel tank systems

6.5.1. Fuel drain and refill

The fuel tank of the vehicle shall be emptied. This shall be done so as not to abnormally purge or abnormally load the evaporative control devices fitted to the vehicle. Removal of the fuel cap is normally sufficient to achieve this. The fuel tank shall be refilled with reference fuel at a temperature of 18 °C ± 2 °C to 40 ± 2 per cent of its nominal capacity.

6.5.2. Soak

Within 5 minutes after completing fuel drain and refill, the vehicle shall be soaked for a minimum of 6 hours and a maximum of 36 hours at 23 °C ± 3 °C.

6.5.3. Preconditioning drive

The vehicle shall be placed on a chassis dynamometer and driven over the following phases of the cycle described in Sub-Annex 1 of Annex XXI:

(a)

For Class 1 vehicles: low, medium, low, low, medium, low

(b)

For Class 2 and 3 vehicles: low, medium, high, medium.

For OVC-HEVs, the preconditioning drive shall be performed under the charge-sustaining operating condition as defined in paragraph 3.3.6. of Annex XXI. Upon the request of approval authority, any other mode may be used.

6.5.4. Fuel drain and refill

Within one hour after the preconditioning drive, the fuel tank of the vehicle shall be emptied. This shall be done so as not to abnormally purge or abnormally load the evaporative control devices fitted to the vehicle. Removal of the fuel cap is normally sufficient to achieve this. The fuel tank shall be refilled with test fuel at a temperature of 18 °C ± 2 °C to 40 ± 2 per cent of its nominal capacity.

6.5.5. Soak

Within five minutes of completing fuel drain and refill, the vehicle shall be parked for a minimum of 12 hours and a maximum of 36 hours at 23 °C ± 3 °C.

During soaking, the procedures described in paragraphs 6.5.5.1. and 6.5.5.2. may be performed either in the order of first paragraph 6.5.5.1. followed by paragraph 6.5.5.2. or in the order paragraph 6.5.5.2. followed by paragraph 6.5.5.1. The procedures described in paragraphs 6.5.5.1. and 6.5.5.2. may also be performed simultaneously.

6.5.5.1. REESS charge

For OVC-HEVs, the REESS shall be fully charged in accordance with the charging requirements described in paragraph 2.2.3. of Appendix 4 to Sub-Annex 8 of Annex XXI.

6.5.5.2. Canister loading

The canister aged in accordance with the sequence described in paragraph 5.1. of this Appendix shall be loaded to 2 gram breakthrough in accordance with the procedure described in paragraph 5.1.4. of Annex 7 of UN/ECE Regulation No 83.

6.5.6. Dynamometer test

The test vehicle shall be pushed onto a dynamometer and shall be driven over the cycles described in paragraph 6.5.3.(a) or paragraph 6.5.3.(b) of this Appendix. OVC-HEVs shall be operated in charge-depleting operating condition. The engine shall be subsequently shut off. Exhaust emissions may be sampled during this operation and the results may be used for the purpose of exhaust emission and fuel consumption type approval if this operation meets the requirement described in Sub-Annex 6 or Sub-Annex 8 of Annex XXI.

6.5.7. Hot soak evaporative emissions test

Within 7 minutes after the dynamometer test and within 2 minutes of the engine being switched off, the hot soak evaporative emissions test shall be performed in accordance with paragraph 5.5. of Annex 7 of UN/ECE Regulation No 83. The hot soak losses shall be calculated in accordance with paragraph 7.1. of this Appendix and included in all relevant test reports as M_HS.

6.5.8. Soak

After the hot soak evaporative emissions test, the test vehicle shall be soaked for not less than 6 hours and not more than 36 hours between the end of the hot soak test and the start of the diurnal emission test. For at least the last 6 hours of this period the vehicle shall be soaked at 20 °C ± 2 °C.

6.5.9. Diurnal testing

6.5.9.1. The test vehicle shall be exposed to two cycles of ambient temperature pursuant to the profile specified for the diurnal emission test in Appendix 2 to Annex 7 of UN/ECE Regulation No 83 with a maximum deviation of ± 2 °C at any time. The average temperature deviation from the profile, calculated using the absolute value of each measured deviation, shall not exceed ± 1 °C. Ambient temperature shall be measured at least every minute and included in all relevant test sheets. Temperature cycling shall begin at time T_start = 0, as specified in paragraph 6.5.9.6. of this Appendix.

6.5.9.2. The enclosure shall be purged for several minutes immediately before the test until a stable background is obtained. The chamber mixing fan(s) shall also be switched on at this time.

6.5.9.3. The test vehicle, with the powertrain shut off and the test vehicle windows and luggage compartment(s) opened, shall be moved into the measuring chamber. The mixing fan(s) shall be adjusted in such a way as to maintain a minimum air circulation speed of 8 km/h under the fuel tank of the test vehicle.

6.5.9.4. The hydrocarbon analyser shall be zeroed and spanned immediately before the test.

6.5.9.5. The enclosure doors shall be closed and sealed gas-tight.

6.5.9.6. Within 10 minutes of closing and sealing the doors, the hydrocarbon concentration, temperature and barometric pressure shall be measured to give initial readings of hydrocarbon concentration in the enclosure C_HCi, barometric pressure P_i and ambient chamber temperature T_i for the diurnal testing. T_start = 0 starts at this time.

6.5.9.7. The hydrocarbon analyser shall be zeroed and spanned immediately before the end of each emission sampling period.

6.5.9.8. The end of the first and second emission sampling period shall occur at 24 hours ±6 minutes and 48 hours ± 6 minutes, respectively, after the beginning of the initial sampling, as specified in paragraph 6.5.9.6. of this Appendix. The elapsed time shall be included in all relevant test reports.

At the end of each emission sampling period, the hydrocarbon concentration, temperature and barometric pressure shall be measured and used to calculate the diurnal test results using the equation in paragraph 7.1. of this Appendix. The result obtained from the first 24 hours shall be included in all relevant test reports as M_D1. The result obtained from the second 24 hours shall be included in all relevant test reports as M_D2.

6.6. Continuous test procedure for sealed fuel tank systems

6.6.1. In the case that the fuel tank relief pressure is greater than or equal to 30 kPa.

6.6.1.1. The test shall be performed as described in paragraphs 6.5.1. to 6.5.3. of this Appendix.

6.6.1.2. Fuel drain and refill

Within one hour after the preconditioning drive, the fuel tank of the vehicle shall be emptied. This shall be done so as not to abnormally purge or abnormally load the evaporative control devices fitted to the vehicle. Removal of the fuel cap is normally sufficient to achieve this, otherwise the canister shall be disconnected. The fuel tank shall be refilled with reference fuel at a temperature of 18 °C ± 2 °C to 15 ± 2 per cent of the tank's nominal capacity.

6.6.1.3. Soak

Within 5 minutes after completing fuel drain and refill, the vehicle shall be soaked for stabilization for 6 to 36 hours at an ambient temperature of 20 °C ± 2 °C.

6.6.1.4. Fuel tank depressurisation

The tank pressure shall be subsequently released so as not to abnormally raise the inside pressure of the fuel tank. This may be done by opening the fuel cap of the vehicle. Regardless of the method of depressurisation, the vehicle shall be returned to its original condition within 1 minute.

6.6.1.5. Canister loading and purge

The canister aged in accordance with the sequence described in paragraph 5.1. of this Appendix shall be loaded to 2 gram breakthrough in accordance with the procedure described in paragraph 5.1.6. of Annex 7 of UN/ECE Regulation No 83, and shall be subsequently purged with 25 ± 5 litres per minute with emission laboratory air. The volume of purge air shall not exceed the volume determined in paragraph 6.6.1.5.1. This loading and purging can be done either (a) using an on-board canister at a temperature of 20 °C or optionally 23 °C, or (b) by disconnecting the canister. In both cases, no further relief of the tank pressure is allowed.

6.6.1.5.1. Determination of maximum purge volume

The maximum purge amount Vol_max shall be determined by the following equation. In the case of OVC-HEVs, the vehicle shall be operated in charge-sustaining operating condition. This determination can also be done at a separate test or during the preconditioning drive.

where:

Vol_Pcycle

is the cumulative purge volume rounded to the nearest 0,1 litres measured using a suitable device (e.g. flowmeter connected to the vent of the carbon canister or equivalent) over the cold start preconditioning drive described in the paragraph 6.5.3. of this Appendix, l;

Vol_tank

is the manufacturer's nominal fuel tank capacity, l;

FC_Pcycle

is the fuel consumption over the single purge cycle described in paragraph 6.5.3. of this Appendix which may be measured in either warm or cold start condition, l/100 km. For OVC-HEVs and NOVC-HEVs, fuel consumption shall be calculated in accordance with paragraph 4.2.1. of Sub-Annex 8 of Annex XXI;

Dist_Pcycle

is the theoretical distance to the nearest 0,1 km of a single purge cycle described in paragraph 6.5.3. of this Appendix, km.

6.6.1.6. Preparation of canister depressurisation puff loss loading

After completing canister loading and purging, the test vehicle shall be moved into an enclosure, either a SHED or an appropriate climatic chamber. It shall be demonstrated that the system is leak-free and the pressurisation is performed in a normal way during the test or by separate test (e.g. by means of pressure sensor on the vehicle). The test vehicle shall be subsequently exposed to the first 11 hours of the ambient temperature profile specified for the diurnal emission test in Appendix 2 to Annex 7 of UN/ECE Regulation No 83 with a maximum deviation of ± 2 °C at any time. The average temperature deviation from the profile, calculated using the absolute value of each measured deviation, shall not exceed ± 1 °C. The ambient temperature shall be measured at least every 10 minutes and included in all relevant test sheets.

6.6.1.7. Canister puff loss loading

6.6.1.7.1. Fuel tank depressurisation before refuelling

The manufacturer shall ensure that the refuelling operation cannot be initiated before the sealed fuel tank system is fully depressurised to a pressure less than 2,5 kPa above ambient pressure in normal vehicle operation and use. At the request of the approval authority, the manufacturer shall provide detailed information or demonstrate proof of operation (e.g. by means of pressure sensor on the vehicle). Any other technical solution may be allowed provided that a safe refuelling operation is ensured and that no excessive emissions are released to the atmosphere before the refuelling device is connected to the vehicle.

6.6.1.7.2. Within 15 minutes after the ambient temperature has reached 35 °C, the tank relief valve shall be opened to load the canister. This loading procedure may be executed either inside or outside an enclosure. The canister loaded in accordance with this paragraph shall be disconnected and shall be kept in the soak area. A dummy canister shall be installed to the vehicle when undertaking the procedure specified in paragraphs 6.6.1.9. to 6.6.1.12. of this Appendix.

6.6.1.8. Measurement of depressurisation puff loss overflow

6.6.1.8.1. Any depressurisation puff loss overflow from the vehicle canister shall be measured by using an auxiliary carbon canister connected directly at the outlet of the vehicle vapour storage unit. It shall be weighed before and after the procedure described in paragraph 6.6.1.7. of this Appendix.

6.6.1.8.2. Alternatively, the depressurisation puff loss overflow from the vehicle canister during its depressurisation may be measured using a SHED.

Within 15 minutes after the ambient temperature has reached 35 °C as described in paragraph 6.6.1.6. of this Appendix, the chamber shall be sealed and the measurement procedure shall be started.

The hydrocarbon analyser shall be zeroed and spanned, after which the hydrocarbon concentration, temperature and barometric pressure shall be measured to give the initial readings C_HCi, P_i and T_i for the sealed tank depressurisation puff loss overflow determination.

The ambient temperature T of the enclosure shall not be less than 25 °C during the measurement procedure.

At the end of the procedure described in paragraph 6.6.1.7.2. of this Appendix, the hydrocarbon concentration in the chamber shall be measured after 60 ± 5 seconds. The temperature and the barometric pressure shall also be measured. These are the final readings C_HCf, P_f and T_f for the sealed tank depressurisation puff loss overflow.

The sealed tank puff loss overflow result shall be calculated in accordance with paragraph 7.1. of this Appendix and included in all relevant test reports.

6.6.1.8.3. There shall be no change in weight of the auxiliary canister or the result of the SHED measurement, within the tolerance of ± 0,5 gram.

6.6.1.9. Soak

After completing puff loss loading, the vehicle shall be soaked at 23 ± 2 °C for 6 to 36 hours to stabilise the vehicle temperature.

6.6.1.9.1. REESS charge

For OVC-HEVs, the REESS shall be fully charged in accordance with the charging requirements described in paragraph 2.2.3. of Appendix 4 to Annex 8 of Annex XXI during the soaking described in paragraph 6.6.1.9. of this Appendix.

6.6.1.10. Fuel drain and refill

The fuel tank of the vehicle shall be drained and filled up to 40 ± 2 per cent of the tank's nominal capacity with reference fuel at a temperature of 18 °C ± 2 °C.

6.6.1.11. Soak

The vehicle shall be subsequently parked for a minimum of 6 hours to a maximum of 36 hours in the soak area at 20 °C ± 2 °C to stabilise the fuel temperature.

6.6.1.12. Fuel tank depressurisation

The tank pressure shall be subsequently released so as not to abnormally raise the inside pressure of the fuel tank. This may be done by opening the fuel cap of the vehicle. Regardless of the method of depressurisation, the vehicle shall be returned to its original condition within 1 minute. After this action, the vapour storage unit shall be connected again.

6.6.1.13. The procedures in paragraphs 6.5.6. to 6.5.9.8. of this Appendix shall be followed.

6.6.2. In the case that the fuel tank relief pressure is lower than 30 kPa

The test shall be performed as described in paragraphs 6.6.1.1. to 6.6.1.13. of this Appendix. However, in this case, the ambient temperature described in paragraph 6.5.9.1. of this Appendix shall be replaced by the profile specified in Table VI.1 of this Appendix for the diurnal emission test.

Table VI.1

Ambient temperature profile of the alternative sequence for sealed fuel tank system

Time (hours)	Temperature (°C)
0/24	20,0
1	20,4
2	20,8
3	21,7
4	23,9
5	26,1
6	28,5
7	31,4
8	33,8
9	35,6
10	37,1
11	38,0
12	37,7
13	36,4
14	34,2
15	31,9
16	29,9
17	28,2
18	26,2
19	24,7
20	23,5
21	22,3
22	21,0
23	20,2

6.7. Stand-alone test procedure for sealed fuel tank systems

6.7.1 Measurement of depressurisation puff loss loading mass

6.7.1.1. The procedures in paragraphs 6.6.1.1. to 6.6.1.7.2. of this Appendix shall be performed. The depressurisation puff loss loading mass is defined as the difference in weight of the vehicle canister before paragraph 6.6.1.6. of this Appendix is applied and after paragraph 6.6.1.7.2. of this Appendix is applied.

6.7.1.2. The depressurisation puff loss overflow from the vehicle canister shall be measured in accordance with paragraphs 6.6.1.8.1. and 6.6.1.8.2. of this Appendix and fulfil the requirements of paragraph 6.6.1.8.3. in this Appendix.

6.7.2. Hot soak and diurnal breathing evaporative emissions test

6.7.2.1. In the case that the fuel tank relief pressure is greater than or equal to 30 kPa

6.7.2.1.1. The test shall be performed as described in paragraphs 6.5.1. to 6.5.3. and paragraphs 6.6.1.9. to 6.6.1.9.1. of this Appendix.

6.7.2.1.2. The canister shall be aged in accordance with the sequence described in paragraph 5.1. of this Appendix and shall be loaded and purged in accordance with paragraph 6.6.1.5. of this Appendix.

6.7.2.1.3. The aged canister shall subsequently be loaded in accordance with the procedure described in paragraph 5.1.6. of Annex 7 of UN/ECE Regulation No 83 with the exemption of loading mass. Total loading mass shall be determined in accordance with paragraph 6.7.1.1. of this Appendix. At the request of the manufacturer, the reference fuel may alternatively be used instead of butane. The canister shall be disconnected.

6.7.2.1.4. The procedures in paragraphs 6.6.1.10. to 6.6.1.13. of this Appendix shall be followed.

6.7.2.2. In the case that the fuel tank relief pressure is lower than 30 kPa

The test shall be performed as described in paragraphs 6.7.2.1.1. to 6.7.2.1.4. of this Appendix. However, in this case, the ambient temperature described in 6.5.9.1. of this Appendix shall be modified pursuant to the profile specified in Table VI.1 of this Appendix for the diurnal emission test.

7. Calculation of evaporative test results

7.1. The evaporative emission tests described in this Annex allow the hydrocarbon emissions from the puff loss overflow, diurnal and hot soak tests to be calculated. Evaporative losses from each of these tests shall be calculated using the initial and final hydrocarbon concentrations, temperatures and pressures in the enclosure, together with the net enclosure volume.

The following equation shall be used:

where:

M_HC

is the mass of hydrocarbons, grams;

M_HC,out

is the mass of hydrocarbons exiting the enclosure in the case of fixed volume enclosures for diurnal emission testing, grams;

M_HC,in

is the mass of hydrocarbon entering the enclosure in the case of fixed volume enclosures for diurnal emission testing, grams;

C_HC

is the measured hydrocarbon concentration in the enclosure, ppm volume in C₁ equivalent;

V

is the net enclosure volume corrected for the volume of the vehicle with the windows and the luggage compartment open, m³. If the volume of the vehicle is not known, a volume of 1,42 m³ shall be subtracted;

T

is the ambient chamber temperature, K;

P

is the barometric pressure, kPa;

H/C

is the hydrogen to carbon ratio

where:

H/C

is taken to be 2,33 for puff loss overflow measurement in SHED and diurnal test losses;

H/C

is taken to be 2,20 for hot soak losses;

k

is 1,2 × 10^{– 4} × (12 + H/C), in (g × K/(m³ × kPa));

i

is the initial reading;

f

is the final reading;

7.2. The result of (M_HS + M_D1 + M_D2 + (2 × PF)) shall be below the limit defined in paragraph 6.1.

8. Test report

The test report shall contain at least the following:

(a)

Description of the soak periods, including time and mean temperatures;

(b)

Description of aged canister used and reference to exact ageing report;

(c)

Mean temperature during the hot soak test;

(d)

Measurement during hot soak test, HSL;

(e)

Measurement of first diurnal, DL1st day;

(f)

Measurement of second diurnal, DL2nd day;

(g)

Final evaporative test result, calculated in accordance with paragraph 7. of this Appendix;

(h)

Declared fuel tank relief pressure of the system (for sealed tank systems);

(i)

Puff loss loading value (in the case of using the stand-alone test described in paragraph 6.7. of this Appendix).’