Document ID: chunk:federal_register_of_legislation:F2024L00447:reg:0:p38
Version: federal_register_of_legislation:F2024L00447
Segment Type: reg
Provision Reference: reg 0 (pt 38/57)
Character Range: 196410–199471

—  mass of the exhaust component 'gas' [g/s]

qmaw,i       —  instantaneous intake air mass flow rate [kg/s]

qm,c         —  time-corrected exhaust mass flow rate [kg/s]

qmew,i       —  instantaneous exhaust mass flow rate [kg/s]

qmf,i        —  instantaneous fuel mass flow rate [kg/s]

qm,r         —  raw exhaust mass flow rate [kg/s]

r            —  cross-correlation coefficient

r2           —  coefficient of determination

rh           —  hydrocarbon response factor

ugas         —  u value of the exhaust component 'gas'

              3. Time correction of parameters

              For the correct calculation of distance-specific emissions, the recorded traces of component concentrations, exhaust mass flow rate, vehicle speed, and other vehicle data shall be time corrected. To facilitate the time correction, data which are subject to time alignment shall be recorded either in a single data recording device or with a synchronised timestamp following paragraph 5.1. of Annex 4. The time correction and alignment of parameters shall be carried out by following the sequence described in paragraphs 3.1. to 3.3.

              3.1. Time correction of component concentrations

              The recorded traces of all component concentrations shall be time corrected by reverse shifting according to the transformation times of the respective analysers. The transformation time of analysers shall be determined according to paragraph 4.4. of Annex 5:

              where:

ci,c   is the time-corrected concentration of component i as function of time t

ci,r   is the raw concentration of component i as function of time t

Δtt,i  is the transformation time t of the analyser measuring component i

              3.2. Time correction of exhaust mass flow rate

              The exhaust mass flow rate measured with an exhaust flow meter shall be time corrected by reverse shifting according to the transformation time of the exhaust mass flow meter. The transformation time of the mass flow meter shall be determined according to paragraph 4.4. of Annex 5:

              where:

qm,c   is the time-corrected exhaust mass flow rate as function of time t

qm,r   is the raw exhaust mass flow rate as function of time t

Δtt,m  is the transformation time t of the exhaust mass flow meter

In case the exhaust mass flow rate is determined by ECU data or a sensor, an additional transformation time shall be considered and obtained by cross-correlation between the calculated exhaust mass flow rate and the exhaust mass flow rate measured following paragraph 4. of Annex 6.
              3.3. Time alignment of vehicle data

Other data obtained from a sensor or the ECU shall be time-aligned by cross-correlation with suitable emission data (e.g., component concentrations).
              3.3.1. Vehicle speed from different sources

To time align vehicle speed with the exhaust mass flow rate, it is first necessary to establish one valid speed trace. In case vehicle speed is obtained from multiple sources (e.g., the GNSS, a sensor or