Clarksville Fire Rescue Assistant Chief Randy Ellis and Capt. Michael Welch each earned their fire officer IV certification. Both fire officers put in more than 100 hours of work, in addition to studying and then challenged a tough test. Fire officer IV is the highest level of certification that a firefighter can get through the Tennessee Fire Commission. Not many people in Tennessee have this certification. They are the 66th and 67th person in Tennessee to receive the certification.