Appendix 4
United Kingdom
Algorithm for the determination of valid events during in-service monitoring
1.
General provisions
1.1.
For the purposes of this Appendix ‘event’ means the data measured in an in-service monitoring test for the gaseous pollutant emissions calculations obtained in a time increment Δt equal to the data sampling period,
1.2.
The methodology set out in this Appendix is based on the concept of working and non-working events.
1.3.
Any event considered as a non-working event in accordance with this Appendix shall not be considered as valid for the calculations of the work or CO2 mass and the gaseous pollutant emissions and conformity factors of the averaging windows set out in Section 2 of Appendix 5. Only working events shall be used for the purpose of calculations.
1.4.
Non-working events shall be categorised as short non-working events (≤ D2) and long non-working events (> D2) (see the Table for the value of D2).
2.
Procedure to determine non-working events
2.1.
The following events shall be considered as non-working events:
- 2.1.1.
Events where the engine power is below 10 % of the engine maximum net power.
- 2.1.2.
Events corresponding to engine system cold conditions (cold start) set out in point 6.4.2 of Appendix 2.
- 2.1.3.
Events logged under ambient conditions not fulfilling the requirements set out in point 3.3 of this Appendix.
- 2.1.4.
Events logged during the periodic checks of the measurement instruments.
2.2.
The following additional steps shall be conducted:
- 2.2.1.
Non-working events shorter than D0 shall be considered as working events and merged with the surrounding working events (see the Table for the values of D0).
- 2.2.2.
The take-off phase following long non-working events (> D2) shall also be considered as a non-working event until the exhaust gas temperature reaches 523 K. If the exhaust gas temperature does not reach 523 K within D3 minutes, all events after D3 shall be considered as working events (see the Table for the values of D3).
- 2.2.3.
For all non-working events, the first D1 minutes of the event shall be considered as working event (see the Table for the values of D1).
3.
‘Machine work’ marking algorithm
3.1.
Step 1
Detect and split into working events and non-working events.
3.1.1.
Define the working events and non-working events in accordance with point 2.
3.1.2.
Calculate the duration of non-working events.
3.1.3.
Mark the non-working events shorter than D0 as working events (see the Table for the values of D0).
3.1.4.
Calculate the duration of the remaining non-working events.
3.2.
Step 2
Merge short working events (≤ D0) into non-working events.
3.2.1.
Merge working events shorter than D0 with the surrounding non-working events of duration longer than D1.
3.3.
Step 3
Exclude working events after long non-working events (take off phase).
3.3.1.
Consider as non-working events those events after long (> D2) non-working events until the exhaust gas temperature reaches 523 K or until D3 minutes have elapsed (see the Table for the values of D3), whatever happens first.
3.4.
Step 4
Include non-working events after working events.
3.4.1.
Include D1 minutes of non-working event at the end of any working event (see the Table for the values of D1).
Table
Values for the parameters D0, D1, D2 and D3
| Parameters | Value |
|---|---|
| D0 | 2 minutes |
| D1 | 2 minutes |
| D2 | 10 minutes |
| D3 | 4 minutes |
4.
Examples
4.1.
Exclusions of non-working data at the end of Step 1
4.2.
Exclusions of non-working data at the end of Step 2
4.3.
Exclusions of non-working data at the end of Step 3
4.4.
End of Step 4 — Final