DUI Metrology Dictionary

Flow monitor (in the context of the Intoxilyzer)

An Intoxilyzer 8000, 8000C, and 5000EN all have air flow systems that need to be properly calibrated at the factory or the Canadian Authorized Service Centre. As with ethyl alcohol calibration, air flow calibration (which affects what you see on the flow monitor) requires a special air pump that is reliable and traceable to reference standards for volume and flow. The flow system in any of these machines can be negligently uncalibrated (I've done it to my 5000EN accidentally). The instrument will still appear to work just fine but the flow monitoring system, fundamental to any refuse/failure to blow charge will be compromised. The flow monitor is available on all Intoxilyzer 8000s and 8000Cs but is only available IN ONTARIO on later software versions to an ordinary qualified technician by an Esc Esc F keyboard entry. It is not available to an ordinary qualified technician IN ONTARIO on older software versions. This is a ridiculous situation. In the United States, the flow monitor indicates flow during the course of every (ACABA and ABA) breath test so that the technician can see (not just guess) the actual volume that the subject is blowing. Resting value or R value is just the floating zero point of the calibration of the flow system depending on both aging hardware and software calibration of flow. See 2013 Training Aid page 144.