The instrument shown in the illustration has not been used for several weeks. Prior to its use for testing a compartment, you should __________. See Illustration SF-0003

Correct Answer: Option D — all of the above

Prior to deploying an explosimeter that has sat idle, technicians must verify battery voltage, purge the internal sampling lines of any residual moisture or vapors, and mechanically or electrically zero the meter pointer to ensure reliable, accurate explosibility readings.