# Commission Implementing Decision of 10 March 2014 on the approval of the light emitting diodes low beam module ‘E-Light’ as an innovative technology for reducing CO2 emissions from passenger cars pursuant to Regulation (EC) No 443/2009 of the European Parliament and of the Council (Text with EEA relevance) (2014/128/EU), Division 4.3: Calculate the statistical error in the CO2 savings

Extent: E+W+S+N.I.

The statistical error in the CO2 savings is to be determined in two steps. In the first step the error value of the power is to be determined as a standard deviation being equivalent to a confidence interval of 68 %.
This is to be done by formula (4).
Formula (4) S x – = ∑ i = 1 n x i − x – 2 n n − 1
Where:
S x – standard deviation of arithmetic mean [W];
xi measurement value [W];
x – arithmetic mean [W];
n number of measurements, which is 10.
Then the error in the CO2 savings is to be determined using the propagation law, which is expressed in formula (5).
Formula (5) ΔC CO 2 – = ∑ i = 1 n ∂C CO 2 ∂P × eP i 2
Where:
ΔCCO2 : mean total error of the CO2 saving (gCO2/km)
∂ CCO2 /∂P sensitivity of calculated CO2 saving related to input value xi
ePi: error of input value (W)
Substituting formula (2) in formula (5) leads for petrol fueled vehicles to:
Formula (6) ΔC CO 2 = 0,0090 gCO 2 ∕ kmW × eP
Where:
ΔCCO2 the error in the CO2 savings (g CO2/km);
eP the error in the power consumption (W).
Substituting formula (2) in formula (5) leads for diesel fueled vehicles to:
Formula (7) ΔC CO 2 = 0,0085 gCO 2 /kmW × eP
Where:
ΔCCO2 the error in the CO2 savings (g CO2/km);
eP error in the power consumption (W).

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Source: https://www.legislation.gov.uk/eudn/2014/128/annex/division/4/division/4.3 (the official version)
Page: https://openlegislation.uk/eu-decision-2014-128/annex/division-4/division-4.3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.