September 2015 drafting meeting not a drafting issue

September 2015 drafting meeting: not a drafting issue. WLTP GTR DRAFTING ISSUES Small group to analyse these proposals. ANNEX 6, APPENDIX 2, § 2. 1. 1. RCB CORRECTION, MEASUREMENT TOLERANCE. BMW #11 Change text regarding tolerance in: Example average current, lower higher peak current [A] 5 15 >200 tolerance [A] 0. 025 0. 075 1. 000 tolerance [A] 0. 2 to measured value to full scale of 200 - Electric current cannot be measured with that accuracy, because: - taking an accurate instrument, it will be magnetized and therefore will have an offset with the first engine start (too high currents); - taking an instrument for high currents, cannot be that accurate. - Tolerance on the measured value is not a technical correct tolerance, only full scale tolerance is valid (while limiting the full scale). WLTP Drafting, BMW, 18. 08. 2015 2. 1. 1. The battery current shall be measured during the tests using a clamp-on or closed type current transducer. The current transducer (i. e. a current sensor without data acquisition equipment) shall have a minimum accuracy of 0. 1 per cent of full scale, and the full scale shall be selected within the maximum electric load and the maximum load + 50%. - There are two solutions: - (1) Exclude current of starting the engine: - small energy error; - measurement accuracy can be maintained; - risk of wrong application (which wire to measure? ). - (2) Increase tolerance; no error in balanced energy; slightly lower accuracy; no risk of wrong application. - Favourite is option (2), which is reflected in the text.