What factor can cause inaccurate readings on the Intoxilyzer 9000?

The presence of mouth alcohol is a significant factor that can lead to inaccurate readings on the Intoxilyzer 9000. This occurs when residual alcohol from recent drinking is still present in the mouth, such as from drinking or rinsing with an alcoholic substance before the breath test. The Intoxilyzer measures not only the alcohol that is in the breath from the lungs but also any alcohol that may be lingering in the oral cavity. If mouth alcohol is present, it can cause the device to give a falsely elevated reading, which does not accurately reflect the individual's blood alcohol concentration (BAC).

In contrast, while high temperatures in the environment can affect the performance of the device, they do not directly introduce alcohol into the breath sample and therefore are not as significant a source of potential error. The age of the tested individual and the type of beverage consumed might influence alcohol metabolism and absorption but are less directly linked to the validity of the breath test results compared to the direct impact of mouth alcohol.