Usually, the
experiment is like:
'SO2' and 'SO4' (It seldom just run
'SO2' only, because the icteraction
between 'SO2' and 'SO4')
'BC_HB' and 'BC_HL'
'OC_HB'
and 'OC_HL'
It's not good to design an experiment of just 'OC_HB', or just 'BC_HL'.
Why do 'chtrname' = 'SO2' ,'SO4' or 'BC_HB', 'BC_HL' or 'OC_HB' ,'OC_HL'?
With Best Regards
GuoGL