Linearity requirements Sample Clauses

Linearity requirements. The linearity requirements shall be verified whenever damage is observed, as required by internal audit procedures or by the instrument manufacturer, at least once within the 12-month period leading up to a test.

Linearity requirements. The PN analyser including the sampling line shall fulfil the linearity requirements of paragraph 3.2. of Annex 5 using monodisperse or polydisperse soot-like particles. The particle size (mobility diameter or count median diameter) shall be larger than 45 nm. The reference instrument shall be an Electrometer or a Condensation Particle Counter (CPC) with d50 = 10 nm or lower, verified for linearity. Alternatively, a particle number system compliant with UN Regulation No. 154 on WLTP. In addition, the differences of the PN analyser from the reference instrument at all points checked (except the zero point) shall be within 15 per cent of their mean value. At least 5 points equally distributed (plus the zero) shall be checked. The maximum checked concentration shall be > 90 per cent of the PN analyser nominal measurement range. If the PN analyser is calibrated in parts, then the linearity can be checked only for the PN detector, but the efficiencies of the rest parts and the sampling line shall be considered in the slope calculation.

Linearity requirements. All analysers, flow-measuring instruments, sensors and signals shall comply with the linearity requirements given in Table A5/1. If air flow, fuel flow, the air-to-fuel ratio or the exhaust mass flow rate is obtained from the ECU, the calculated exhaust mass flow rate shall meet the linearity requirements specified in Table A5/1. Table A5/1 Measurement parameter/instrument |𝑥𝑚𝑖𝑛 × (𝑎1 − 1) + 𝑎0| Slope a1 Standard error of the estimate SEE Coefficient of determination r2 Fuel flow rate1 ≤ 1 % xmax 0.98 – 1.02 ≤ 2 % of xmax ≥ 0.990 Air flow rate2 ≤ 1 % xmax 0.98 – 1.02 ≤ 2 % of xmax ≥ 0.990 Exhaust mass flow rate ≤ 2 % xmax 0.97 – 1.03 ≤ 3 % of xmax ≥ 0.990 Gas analysers ≤ 0.5 % max 0.99 – 1.01 ≤ 1 % of xmax ≥ 0.998 Torque3 ≤ 1 % xmax 0.98 – 1.02 ≤ 2 % of xmax ≥ 0.990 PN analysers4 ≤ 5 % xmax 0.85 – 1.155 ≤ 10 % of xmax ≥ 0.950 1 optional to determine exhaust mass flow.

Linearity requirements. The calibration of all measuring instruments and systems shall be traceable to national (international) standards. The measuring instruments and systems shall 2.1. shall be performed for the gas analysers at least every 3 months or whenever a system repair or change is made that could influence calibration. For the other instruments and systems, the linearity verification shall be done as required by internal audit procedures, by the instrument manufacturer or in accordance with ISO 9000 requirements. Measurement system Intercept b Slope m Standard error SEE Coefficient of determination r2 Engine speed ≤ 0.05 % max 0.98 - 1.02 ≤ 2 % max ≥ 0.990 Engine torque ≤ 1 % max 0.98 - 1.02 ≤ 2 % max ≥ 0.990 Fuel flow ≤ 1 % max 0.98 - 1.02 ≤ 2 % max ≥ 0.990 Airflow ≤ 1 % max 0.98 - 1.02 ≤ 2 % max ≥ 0.990 Exhaust gas flow ≤ 1 % max 0.98 - 1.02 ≤ 2 % max ≥ 0.990 Dilution airflow ≤ 1 % max 0.98 - 1.02 ≤ 2 % max ≥ 0.990 Diluted exhaust gas flow ≤ 1 % max 0.98 - 1.02 ≤ 2 % max ≥ 0.990 Sample flow ≤ 1 % max 0.98 - 1.02 ≤ 2 % max ≥ 0.990 Gas analysers ≤ 0.5 % max 0.99 - 1.01 ≤ 1 % max ≥ 0.998 Gas dividers ≤ 0.5 % max 0.98 - 1.02 ≤ 2 % max ≥ 0.990 Temperatures ≤ 1 % max 0.99 - 1.01 ≤ 1 % max ≥ 0.998 Pressures ≤ 1 % max 0.99 - 1.01 ≤ 1 % max ≥ 0.998 PM balance ≤ 1 % max 0.99 - 1.01 ≤ 1 % max ≥ 0.998