What must be ensured regarding the subject's mouth before administering the test?

Ensuring that the mouth is free from any foreign objects is crucial before administering the Intoxilyzer 9000 test because foreign objects can interfere with the accuracy of the breath test results. Objects such as gum, tobacco, or food particles can affect the amount of alcohol vapors that are exhaled, leading to false readings. The integrity of the breath sample is vital; any obstruction could cause contamination or alter the concentration of alcohol in the breath, which is ultimately what the device measures.

By confirming that the mouth is clear, operators can guarantee that the test will reflect the subject's actual blood alcohol content more accurately, fulfilling the test's purpose of measuring intoxication levels effectively.