How should an operator prepare the machine before conducting a breath test?

Preparing the Intoxilyzer 9000 before conducting a breath test involves performing a self-test and ensuring that the machine is properly calibrated. This step is crucial because the self-test checks the internal components of the machine to confirm that it is functioning correctly. Calibrating the machine ensures that it is accurately measuring blood alcohol content (BAC) and that it provides reliable results. Calibration typically requires adjusting the machine using known standards to ensure its accuracy, which is essential for maintaining the integrity of the testing process.

Other options, while they may seem relevant, do not address the critical initial steps required for preparing the machine. Creating a controlled lighting environment does not impact the actual operation of the Intoxilyzer. Collecting random samples is not a preparation step; rather, it pertains to the procedure following the machine's readiness. Lastly, calibrating the machine only once a month would not suffice, as regular calibration is needed to maintain accuracy and reliability across testing sessions.