5.1.4.9. The end of the emission sampling period occurs t1 + t2 or t1 + 5 hours after the beginning of the initial sampling, as specified in paragraph 5.1.4.6. of this annex. The different times elapsed are recorded. The hydrogen concentration, temperature and barometric pressure are measured to give the final readings CH2f , Tf and Pf for the normal charge test, used for the calculation in paragraph 6. of this annex. a0c0