Legislation Sections Database at defencecounsel.com for:
Criminal Code of Canada
(3) If a peace officer has reasonable grounds to believe that a person is committing, or at any time within the preceding three hours has committed, an offence under section 253 as a result of the consumption of alcohol, the peace officer may, by demand made as soon as practicable, require the person
(a) to provide, as soon as practicable,
(i) samples of breath that, in a qualified technician's opinion, will enable a proper analysis to be made to determine the concentration, if any, of alcohol in the person's blood, or
(ii) if the peace officer has reasonable grounds to believe that, because of their physical condition, the person may be incapable of providing a sample of breath or it would be impracticable to obtain a sample of breath, samples of blood that, in the opinion of the qualified medical practitioner or qualified technician taking the samples, will enable a proper analysis to be made to determine the concentration, if any, of alcohol in the person's blood; and
(b) if necessary, to accompany the peace officer for that purpose.
Please note that qualified technicians is entitled to demand "samples". The number of samples is usually two but may be 3, 4, 5, 6, 7, or even 8.
Where more than two samples are obtained the qualified technician should not be completing a Certificate of Qualified Technician but rather should come to Court and give "viva voce" evidence.
Note that the number and quality of samples demanded is "in the opinion of the qualified ... technician necessary to enable proper analysis". It appears that this means that the qualified technician can keep asking you to blow until you consistently blow over 80, even though the instrument has accepted breath samples from you that are below 80. In Ontario the qualified technician can see what you are blowing while you blow and so has the capability of aborting a good breath test under 80.
On the Intoxilyzer 8000C the Ontario software permits the qualified technician to answer the question: Suitable Sample: Y or N following the receipt by the instrument of a breath sample that the instrument has already deemed acceptable as to pressure, time, and slope. Since the breath tech has already seen the instantaneous results of the analysis as the breath is sampled the technician is at that point in a very good position to declare the sample "Unsuitable" if the result is not what he or she wants i.e. over 100 and within 20 mg/100 mls truncated of a prior sample. The instrument has accepted the sample using all of its internal diagnostics and its automatic systems and yet the breath tech is in a position to declare the sample "unsuitable". This seems unfair. The qualified technician in such a case should be asked to provide objective indicia of why the breath sample was declared by him or her to be "unsuitable".