Council Directive of 20 March 1970 on the approximation of the laws of the Member States on measures to be taken against air pollution by emissions from motor vehicles (70/220/EEC) (repealed)

[F1 Appendix 8 CALCULATION OF THE EMISSION OF POLLUTANTS

Textual Amendments

F1 Substituted by Council Directive of 26 June 1991 amending Directive 70/220/EEC on the approximation of the laws of the Member States relating to measures to be taken against air pollution by emissions from motor vehicles (91/441/EEC).

1. GENERAL U.K.

1.1. Emissions of gaseous pollutants are calculated by means of the following equation: U.K.

( ¹ )

where:

M _i

=

mass emission of the pollutant i in grams per kilometre,

V _mix

=

volume of the diluted exhaust gas expressed in litres per test and corrected to standard conditions (273,2 K and 101,33 kPa),

Q _i

=

density of the pollutant i in grams per litre at normal temperature and pressure (273,2 K and 101,33 kPa),

k _H

=

humidity correction factor used for the calculation of the mass emissions of oxides of nitrogen (there is no humidity correction for HC and CO),

C _i

=

concentration of the pollutant i in the diluted exhaust gas expressed in ppm and corrected by the amount of the pollutant i contained in the dilution air,

d

=

actual distance corresponding to the operating cycle in km.

1.2. Volume determination U.K.

1.2.1. Calculation of the volume when a variable dilution device with constant flow control by orifice or venturi is used. Record continuously the parameters showing the volumetric flow, and calculate the total volume for the duration of the test. U.K.

1.2.2. Calculation of volume when a positive displacement pump is used. The volume of diluted exhaust gas in systems comprising a positive displacement pump is calculated with the following formula: U.K.

where:

V

=

volume of the diluted exhaust gas expressed in litres per test (prior to correction),

V _o

=

volume of gas delivered by the positive displacement pump on testing conditions in litres per revolution,

N

=

number of revolutions per test.

1.2.3. Correction of the diluted exhaust-gas volume to standard conditions. The diluted exhaust-gas volume is corrected by means of the following formula: U.K.

( ² )

in which:

( ³ )

where:

P _B

=

barometric pressure in the test room in kPa,

P ₁

=

vacuum at the inlet to the positive displacement pump in kPa relative to the ambient barometric pressure,

T _p

=

average temperature of the diluted exhaust gas entering the positive displacement pump during the test (K).

1.3. Calculation of the corrected concentration of pollutants in the sampling bag U.K.

( ⁴ )

where:

C _i

=

concentration of the pollutant i in the diluted exhaust gas, expressed in ppm and corrected by the amount of i contained in the dilution air,

C _e

=

measured concentration of pollutant i in the diluted exhaust gas, expressed in ppm,

C _d

=

measured concentration of pollutant i in the air used for dilution, expressed in ppm,

DF

=

dilution factor.

[F2 The dilution factor is calculated as follows:

Textual Amendments

F2 Substituted by Commission Directive 98/77/EC of 2 October 1998 adapting to technical progress Council Directive 70/220/EEC on the approximation of the laws of the Member States relating to measures to be taken against air pollution by emissions from motor vehicles (Text with EEA relevance).

]

in this equation:

C _{CO 2}

=

concentration of CO ₂ in the diluted exhaust gas contained in the sampling bag, expressed in % volume,

C _HC

=

concentration of HC in the diluted exhaust gas contained in the sampling bag, expressed in ppm carbon equivalent,

C _CO

=

concentration of CO in the diluted exhaust gas contained in the sampling bag, expressed in ppm.

1.4. Determination of the NO humidity correction factor U.K.

In order to correct the influence of humidity on the results of oxides of nitrogen, the following calculations are applied:

( ⁶ )

in which:

where:

H

=

absolute humidity expressed in grams of water per kilogram of dry air,

R _a

=

relative humidity of the ambient air expressed as a percentage,

P _d

=

saturation vapour pressure at ambient temperature expressed in kPa,

P _B

=

atmospheric pressure in the room, expressed in kPa.

1.5. Example U.K.

1.5.1. Data U.K.

1.5.1.1. Ambient conditions: U.K.

ambient temperature: 23 °C = 296,2 K,

barometric pressure: P _B  = 101,33 kPa,

relative humidity: R _a  = 60 %,

[F3 saturation vapour pressure: P _d = 2,81 kPa of H ₂ O at 23 °C.]

Textual Amendments

F3 Substituted by Commission Directive 96/44/EC of 1 July 1996 adapting to technical progress Council Directive 70/220/EEC on the approximation of the laws of the Member States relating to measures to be taken against air pollution by emissions from motor vehicles (Text with EEA relevance).

1.5.1.2. Volume measured and reduced to standard conditions (paragraph 1) U.K.

V = 51,961 m ³

1.5.1.3. Analyzer readings: U.K.

a In ppm carbon equivalent.
	Diluted exhaust	Dilution-air
HC a	92 ppm	3,0 ppm
CO	470 ppm	0 ppm
NO x	70 ppm	0 ppm
CO 2	1,6 % vol	0,03 % vol

1.5.2. Calculation U.K.

[F3 1.5.2.1. Humidity correction factor (K _H ) (see formula (6)) U.K.

H = 10,5092

k _H = 0,9934]

1.5.2.2. Dilution factor (DF) (see formula (5)) U.K.

DF = 8,091

1.5.2.3. Calculation of the corrected concentration of pollutants in the sampling bag: U.K.

HC, mass emissions (see formulae (4) and (1))

C = 89,371

[F2 Q _HC = 0.619 in the case of petrol or diesel

Q _HC = 0.649 in the case of LPG

Q _HC = 0.714 in the case of NG]

CO, mass emissions (see formula (1))

Q _CO  = 1,25

NO _x mass emissions (see formula (1))

Q _{NO x}  = 2,05

[F3

]

2. SPECIAL PROVISIONS RELATING TO VEHICLES EQUIPPED WITH COMPRESSION-IGNITION ENGINES U.K.

2.1. HC measurement for compression-ignition engines U.K.

The average HC concentration used in determining the HC mass emissions from compression-ignition engines is calculated with the aid of the following formula:

( ⁷ )

where:

=

integral of the recording of the heated FID over the test (t ₂  - t ₁ ),

C _e

=

concentration of HC measured in the diluted exhaust in ppm of C _i ,

C _i is substituted directly for C _HC in all relevant equations.

2.2. Determination of particulates U.K.

Particulate emission M _p (g/km) is calculated by means of the following equation:

where exhaust gases are vented outside tunnel,

where exhaust gases are returned to the tunnel,

where:

V _mix

:

volume of diluted exhaust gases (see 1.1), under standard conditions,

V _ep

:

volume of exhaust gas flowing through particulate filter under standard conditions,

P _e

:

particulate mass collected by filters,

d

:

actual distance corresponding to the operating cycle in km,

M _p

:

particulate emission in g/km.]