Document ID: chunk:federal_register_of_legislation:F2024L00447:reg:0:p20
Version: federal_register_of_legislation:F2024L00447
Segment Type: reg
Provision Reference: reg 0 (pt 20/57)
Character Range: 147039–150269

least squares linear regression parameters, with the best-fit equation having the form:

                  where:

              y is the actual value of the measurement system

              a1 is the slope of the regression line

              x is the reference value

              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.

                  (h) The linear regression parameters shall meet the requirements specified in Table A5/1.

              3.4.3. Requirements for linearity verification on a chassis dynamometer

              Non-traceable flow-measuring instruments, sensors or ECU signals, that cannot directly be calibrated according to traceable standards, shall be calibrated on a chassis dynamometer. The procedure shall follow, as far as applicable, the requirements of UN Regulation No. 154 on WLTP. If necessary, the instrument or sensor to be calibrated shall be installed on the test vehicle and operated according to the requirements of Annex 4. The calibration procedure shall follow whenever possible the requirements of paragraph 3.4.2. At least 10 appropriate reference values shall be selected as to ensure that at least 90 per cent of the maximum value expected to occur during the RDE test is covered.

              If a non-traceable flow-measuring instrument, sensor or ECU signal for determining exhaust flow is to be calibrated, a reference exhaust mass flow meter with traceable calibration or the CVS shall be attached to the vehicle's tailpipe. It shall be ensured that the vehicle exhaust is accurately measured by the exhaust mass flow meter according to paragraph 3.4.3. of Annex 4. The vehicle shall be operated by applying constant throttle at a constant gear selection and chassis dynamometer load.

              4. Analysers for measuring gaseous components

              4.1. Permissible types of analysers

              4.1.1. Standard analysers

              The gaseous components shall be measured with analysers specified in paragraph 4.1.4., Annex B5 to UN Regulation No. 154 on WLTP. If an NDUV analyser measures both NO and NO2, a NO2/NO converter is not required.

              4.1.2. Alternative analysers

              Any analyser not meeting the design specifications of paragraph 4.1.1. is permissible provided that it fulfils the requirements of paragraph 4.2. The manufacturer shall ensure that the alternative analyser achieves an equivalent or higher measurement performance compared to a standard analyser over the range of pollutant concentrations and co-existing gases that can be expected from vehicles operated with permissible fuels under moderate and extended conditions of valid RDE testing as specified in paragraphs 5., 6. and 7. of this annex. Upon request, the manufacturer of the analyser shall submit in writing supplemental information, demonstrating that the measurement performance of the alternative analyser is consistently and reliably in line with the measurement performance of standard analysers. Supplemental information shall contain:

                  (a)