Document ID: chunk:federal_register_of_legislation:F2024L00447:reg:0:p36
Version: federal_register_of_legislation:F2024L00447
Segment Type: reg
Provision Reference: reg 0 (pt 36/57)
Character Range: 190610–193606

PEMS validation results shall fulfil the requirements given in Table A6/1. If any permissible tolerance is not met, corrective action shall be taken and the PEMS validation shall be repeated.

       Table A6/1
       Permissible tolerances

Parameter [Unit]   Permissible absolute tolerance
Distance [km][23]  250 m of the laboratory reference

THC[24] [mg/km]    15 mg/km or 15 % of the laboratory reference, whichever is larger

CH42 [mg/km]       15 mg/km or 15 % of the laboratory reference, whichever is larger

NMHC2 [mg/km]      20 mg/km or 20 % of the laboratory reference, whichever is larger

PN2 [#/km]         8•1010 p/km or 42 % of the laboratory reference[25] whichever is larger

CO2 [mg/km]        100 mg/km or 15 % of the laboratory reference, whichever is larger

CO2 [g/km]         10 g/km or 7.5 % of the laboratory reference, whichever is larger

NOX2 [mg/km]       10 mg/km or 12.5 % of the laboratory reference, whichever is larger

4. Validation procedure for the exhaust mass flow rate determined by non-traceable instruments and sensors
              4.1. Frequency of validation

              In addition to fulfilling the linearity requirements of paragraph 3. of Annex 5 under steady-state conditions, the linearity of non-traceable exhaust mass flow meters or the exhaust mass flow rate calculated from non-traceable sensors or ECU signals shall be validated under transient conditions for each test vehicle against a calibrated exhaust mass flow meter or the CVS.

              4.2. Validation procedure

              The validation shall be conducted on a chassis dynamometer under type approval conditions, as far as applicable on the same vehicle used for the RDE test. As reference, a flow meter with traceable calibration shall be used. The ambient temperature can be any within the range specified in paragraph 8.1. of this Regulation. The installation of the exhaust mass flow meter and the execution of the test shall fulfil the requirement of paragraph 3.4.3. of Annex 4.

              The following calculation steps shall be taken to validate the linearity:

                  (a) The signal under validation and the reference signal shall be time corrected by following, as far as applicable, the requirements of paragraph 3. of Annex 7.

                  (b) Points below 10 per cent of the maximum flow value shall be excluded from the further analysis.

                  (c) At a constant frequency of at least 1.0 Hz, the signal under validation and the reference signal shall be correlated using the best-fit equation having the form:

                  where:

y   is the actual value of the signal under validation

a1  is the slope of the regression line

x   is the actual value of the reference signal

a0  is the y intercept of the regression line

The standard error of estimate (SEE) of y on x and the coefficient of determination (r2) shall be calculated for each measurement parameter and system.
                  (d) The linear