Instruments require regular maintenance by laboratory personnel, and sometimes by qualified repair technicians. The instrument manufacturer will provide recommendations for how often to perform maintenance; those recommendations should be followed. Generally, a log book will document the details of the maintenance:

• date
• time
• name of employee or service engineer
• description of maintenance done, including listing any parts replaced
• description of problems encountered
• description of steps taken to resolve the problem and verify the instrument is functioning, after the changes were made

Instrument logs should be regularly reviewed by supervisors to monitor instrument performance. By reviewing the logs, the supervisor can make changes to the maintenance schedule, based on the frequency of breakdowns.