Look at the wavelength selector. Examine the condition of the optics. Verify the wavelength reading and absorbance level. Check the aspirator. Determine what the instrument is going to be used for It is important to determine what you need in a unit.
Graphite furnace unitswill give greater sensitivity and are the only way to go for someapplications.
Flame units are excellent for many applications. The SC for copper on a flame unitis 4 ppm. 100 and1000 ppm and 6 are greater than 1000 ppm. A common sense check will give some indication of the workhistory of the unit. A paint job can indicatemaintenance or it can indicate service in a harsh environment.