An ABA sequence run by the qualified technician at start of shift or before the subject test where the QT supplies his or her own breath into the Intoxilyzer. The sequence is commenced using the keyboard Esc Esc "B". QTs sometimes use this sequence to demonstrate blowing procedure to the subject. The sequence is Air Blank, Breath Test, Air Blank rather than Air Blank, Cal Check, Air Blank, Breath Test, Air Blank - there is no self-contained cal. check in an ABA. ABA is also used during annual (we hope) maintenance to conduct control tests at values other than 100. ABA tests do not appear in the versions of COBRA data used in Ontario.