Question 60Safety & Environmental - 1st Asst/Chief

The correct answer is D) all of the above. When an instrument has not been used for several weeks, it is important to thoroughly check and prepare it before use to ensure accurate and reliable readings. This involves: 1) Checking or renewing the batteries to ensure the instrument has sufficient power to operate properly. 2) Purging the meter to remove any contaminants or residue that may have built up during the period of non-use. 3) Adjusting the meter pointer to zero to establish a proper baseline for taking measurements. Performing all these steps helps to confirm the instrument is in good working order and will provide accurate results when testing a compartment. The other answer choices, while potentially useful steps, do not encompass the full scope of preparation required for an instrument that has been idle for an extended period.